I’ve set up this page to share information on the conversion of a 2019 Ford Transit cargo van into a 4×4 adventure camper van (aka The Traveling Cat Adventure Vehicle II). We downsized from our 25 ft long, Sprinter-based RV, a Leisure Travel Vans Unity. Our two biggest wishes were to 1) have internal storage for our mountain bikes and 2) have a smaller, more off-road-capable camper van that would allow us to continue down some roads that we would previously have to give up on and that would also allow us to park a little more easily in busy metro areas.
Van Haus Conversions did the bulk of the build out to a camper van. The design features a queen-sized raised-platform bed that runs length-wise and creates a large “garage” space for bikes and gear underneath, leaving a living space with a galley (sink, refrigerator, cooktop) and a seating area surrounding the fold-out swiveling table between the two front swiveling seats and a small bench seat that hides a dry composting toilet.
I was originally attracted to Van Haus when I saw their “Watson” layout that incorporated a dinette seating area, a garage/bike storage area and a galley and hidden toilet into the smaller, non-extended Transit van. However, I eventually decided that we just carry too much bulky stuff (mountain bikes and gear, inflatable kayak and gear, telescope and gear, camp folding chairs, grill, plus space for the cats’ litter box) to be able to get by with that layout. Hence the switch to the platform bed arrangement with the large storage space underneath.
Van Haus was great to work with as they’re very open to accommodating any custom requests, unlike some more well known outfitters – and their craftsmanship looks to be very good. (Here’s some pictures of the work as it progressed.)
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Maintenance / Tips
Wish List / Future Possibilities
Over the course of a year or so, I must have checked out easily more than a hundred van builds from both DIY-ers and professional outfitters. Eventually I settled on going with the gas-powered Ford Transit over the Sprinter or the Promaster. The Promaster was out because of its low ground clearance and I steered away from the Sprinter despite its popularity because I was tired of dealing with diesel emissions issues on our Sprinter-based Unity. (What I really want is a fully battery electric drivetrain in a van with 350+ miles range! As of 2020, that’s not available from anyone yet.)
I wanted the non-extended long body (19.5 feet long, 148″ wheelbase) because I didn’t want to lose off-road maneuverability with that extended length overhang or the ability to park easily in metro areas. I chose the high roof model to allow me to stand upright without hitting the ceiling (I’m 6’4″) and to provide more space above a raised platform bed.
I looked around for an available Transit in this configuration (either used or on a dealer’s lot) but all of the vans I could find were either very basic work vans with no options or they were maxed out with every option including dark paint colors and glass rear cargo doors. I wanted to avoid any dark exterior color to help reflect heat in the hot sun and, for the same reason, I didn’t want glass windows in the rear cargo doors. We found in the Unity that it was very helpful to park with the windowless rear of the Unity towards the sun to keep the interior relatively cool. (It was also extremely helpful to partition off the cab area from the house area with a heavy blanket to keep out the heat.) I also didn’t want to pay for the full featured 2019 radio/navigation unit as I was planning to swap it out with a better aftermarket system. It sounds like the 2020 audio/nav system may be more worthwhile though.
Anyway, I ended up having to configure a custom order from the factory and wait. The ordering process with Ford was complicated by an incredibly long list of often conflicting and poorly documented options and packages. I ended up with just the following packages and additions on top of the standard features:
I ended up ordering a Transit in June of 2019 with delivery expected in November – still a little before the 2020 version with all wheel drive would become available. Rather than wait even longer for that somewhat unknown product, I made plans to have the van converted to four wheel drive by QuadVan in Portland, Oregon.
QuadVan also raised the low-hanging rear shock mounts, upgraded the suspension components, gave the body a 2″ lift, added both front and rear locking differentials, added protective skid plates, installed larger all terrain tires (see below) and switched out the gear ratio to 3.73 to better match the larger circumference tires. (Here’s a gear ratio calculator.) As a result, the van is certainly a more serious 4×4 vehicle, although many of these changes could also be applied to the factory all wheel drive build.
- 4×4 QuadVan conversion w/manual shift high/low
- Front axle: Eaton Detroit Truetrac Locker
- Rear axle: Eaton Detroit Truetrac, ratio change to 3.73
- Van Compass leaf springs
- Raise rear shock mounts
- Bilstein front struts and rear shocks
- 2″ body lift
- Skid plates under front and middle sections and under gas tank
As part of the goal of making this a 4×4 adventure camper van, I researched larger all terrain tire options. From the factory, the van came with relatively small, highway-oriented Continental VanContact A/S 235/65R16 all season tires and simple steel wheels.
Looking over the Transit forum, I found lots of discussion of various larger, all terrain tire options but some of these sizes or models can require modifications to the van. I settled on BF Goodrich All Terrain KO2’s at 245/75R16 which did require a little trimming to a corner of the front wheel well (which QuadVan took care of) and also which appeared to be the largest size that could still be made to fit the spare in the space under the van, albeit with the help of a ratchet strap.
I also got some really nice-looking, black-painted, 16-inch Ultra Toil aftermarket wheels from TireRack to replace the plain factory steel wheels.
However, it turned out that getting one of those KO2’s at that size in the spare tire carrier under the non-extended length van wasn’t so easy after all. After trying various suggested tricks, I ended up selling the barely used KO2’s and getting the slightly smaller Cooper Discoverer AT3’s in LT 245/70R16 which fit fine in the spare tire carrier – no tricks with deflating them or compressing them with a ratchet strap.
Another option to handle those larger KO2’s would be to install a tire carrier on the rear doors, like this one from Aluminess. I actually started going down that route at the suggestion of Erik from Van Haus Conversions, but then decided I really didn’t want the oh-so-rarely used spare hanging on the back door all the time and preventing the door from being opened all the way to the side of the van.
I did not end up driving the van again until after the 4×4 conversion and the camper van build was complete, but when I did I immediately noticed that the handling had changed and become very uncomfortable. Even after it was fully loaded with our gear, we found that at highway speeds (60+ mph), any little curve or steering input (even staying within our lane) made the rear of the van feel like it wanted to swing out. The van felt fine and normal maneuvering at slow speeds but at highway speeds it was seriously unnerving both behind the wheel and riding as a passenger. It felt like you had to slow down below highway speeds even for very mild highway curves and, until you quickly learned to make very minute steering inputs, you’d easily fall into a series of over-corrections as the van wanted to swing one way and then the other.
Apparently this is body roll brought on by the higher center of gravity from the camper van build and perhaps the suspension changes. For what it’s worth, we never experienced this with our larger Sprinter-based Unity RV but then it did have dually wheels and a rear anti-sway bar. After talking to John at QuadVan and someone at my local 4×4 shop here in Scotts Valley, I’ve ordered a Hellwig rear sway bar to try to address this:
Looking on the Transit forum, I do see other folks have experienced excessive body roll and have installed either the Ford anti-sway bar or the Hellwig but also plenty of folk saying they’ve never had an issue and think it’s unnecessary. (I’ve gone with the Hellwig version as it’s both adjustable and larger/stronger.) There are reports of failures with the older design of the Hellwig on the Transit, but this has been supposedly addressed with an updated design that uses a pass-through bolt through the van frame now.
Fingers crossed on the Hellwig sway bar fixing this terrible handling! I’ll update this once it’s installed and I have a chance to drive it.
I opted for Amp Research’s really great powered/retracting steps or running boards. These tuck up and out-of-the-way to give you better ground clearance. This is apparently not a particularly easy install but Van Haus Conversions installed mine.
One thing to note is that they take over the OBD (on-board diagnostics) port under the dash for power and control signals. This became an issue when I went to install my stereo/nav unit upgrade which also makes use of the OBD II / OBD 2 port for the iDatalink features. However, you can install a splitter to allow both to access the OBD signals. Amp Research sells an expensive one but I found a $10 version that seems to work just fine.
- Amp Research Powersteps for both driver and passenger sides (paid link) or see Amp Research’s web page
- OBD2 Splitter (paid link)
We noticed right away on the initial drive back from Oregon that the stock headlight lamps are pretty pathetic – at least if you’re used to modern headlights. I looked into getting some high powered LED lamps off Amazon but it seemed like there were mixed reviews on all of them with issues like fan noise, compatibility issues, early failures, etc. so I just ended up grabbing a pack of Sylvania SilverStar Ultra (paid link) replacement bulbs which are supposed to be among the brightest halogen bulbs available. They do seem to be an improvement, though not as nice as some of the white, high intensity headlamps I’ve experienced on other vehicles.
Installation is straight-forward – just try to avoid dropping and losing a socket down into the engine compartment as I did – never did find it again.
As part of our Van Haus build, swivel platforms were added to both the driver and passenger seats to make it possible to sit around the table. Van Haus chose the swivel platforms from SwivelsRUs. I had ordered the collapsible parking brake from the Transit factory so that a driver’s swivel seat wouldn’t be an issue. (Apparently it is possible to lower the standard parking brake – see FarOutRide’s instructions.)
When we first picked up the van from Van Haus, we noticed that the seats were a little difficult to swivel compared to our previous Sprinter-based RV but didn’t worry about it at the time. However, in the coming weeks, the seats became almost impossible to rotate while sitting on them – it would take all the effort I could put into them and they were nearly as difficult to rotate when not seated in them. It also became apparent that the plastic disc that was sandwiched between the two plates was getting rubbed raw and marred. I pointed out this issue to Erik at Van Haus, but he merely seemed to think that we were turning them the wrong way or binding up the wires – neither was true.
Against Erik’s warnings, I ended up loosening the bolts that sandwiched the plastic rotation plate and spraying some silicon lubricant in between and this immediately freed up the swivel action. It was now possible to rotate the seat freely while sitting or not. However, this also seemed to introduce a bit of play in the seat – even after tightening the bolts back down. The platform can now shift ever so slightly (with an audible clank).
Looking on the web, I found that the folks at FarOutRide.com had done a comparison of the four swivel platform options, including the ones we have from SwivelsRUs. They found that all four had some degree of free play or wobble. They actually used the SwivelsRUs model for over two years before switching it out for the Scopema model mostly because of how it’s 1-1/4″ lower and “went from a kind-of-awkward-but-that’s-OK driving position back to a normal driving position” and feel that it’s much better for driving comfort. That sounds tempting and I may try it eventually. I am certainly experiencing discomfort in my driving position but I think it’s because of how I can’t put the seat back far enough to extend my legs comfortably. (More on that later.)
I should note that Van Haus decided to move the jack that was originally stored under the passenger seat to a cabinet in the garage portion but after investigating it, I found that it was no trouble to insert or remove the jack from under the seat by merely adjusting the seat fully forward. So, to save space elsewhere, I moved the jack back and added a couple of other related items under the seat, like the tire repair kit. There’s lots of space there and it’s easy enough to get into – shame to use precious cabinet space elsewhere.
|In 2019, the available factory options for the radio/stereo/navigation unit weren’t great and the display screen was rather small. (The screen size is particularly important for easily viewing the rear view while backing up.) It sounds like the 2020+ models have a better option now, but for the 2019 build I chose the just-above-base AM/FM/CD w/screen model which was supposedly easier to swap out for an aftermarket system than the absolute base unit. Unfortunately, this base build didn’t include steering wheel controls.
By the time the van conversion was finished, several aftermarket car stereo systems were just coming out that provided large, oversized, “floating” displays that could be mounted from a normal single or double DIN opening. Sweet! I decided to go with a Kenwood model that offered a 10″ screen, wireless CarPlay as well as built-in navigation support (in addition to that provided through Apple CarPlay or Android Auto) and integration with Kenwood’s separate forward dash camera unit. It also supports iDatalink Maestro which provides access to vehicle information (engine temps, tire pressures, etc).
Crutchfield is really nice for ordering car stereo upgrades since they’ll also identify and package up all the necessary fascia and wiring kits for your particular vehicle. Most of the provided kit worked well except that the replacement fascia (Metra 99-5835G Dash Kit) has a terrible clip system for securing the piece to the dash. Many of the clips were very difficult to secure and fit poorly, many of them even popped out and were lost to the innards of the dash in the process of test fitting things together and one clip point broke entirely. I ended up adapting some of the clips from the original dashboard pieces and jury-rigging others to get things to secure in place. It was quite the unnecessary pain.
You’ll find that initially the screen won’t fit the Transit’s dashboard in its factory configuration but the unit comes with an additional, extended mounting bracket (and instructions) to allow the screen to be installed with room to spare.
I secured the GPS antenna underneath the replacement top dashboard piece that fits behind the display screen to give it a clear view of open sky through the windshield.
For the provided microphone, I routed it up to the overhead console. There’s a slot for a factory microphone inside the overhead console and I secured the microphone in there pointing towards the air holes in the slot and sealed it off behind the microphone. Testing the microphone in this location proved that it worked well for phone calls – I was easily heard even while driving. I routed the microphone wire (along with the dash camera cable) along the ceiling fascia, down the A pillar behind the air bags and just under the top of the dashboard to the mounting location for the receiver. There’s an easy to open access panel on the top of the dashboard behind the steering wheel for doing this.
Removing the A pillar covers takes mostly a lot of force but even so, the driver side was extremely difficult to fully release because two of the clips are unlike all the others and seem to be designed to not be able to be removed once clipped. I don’t have any advice here even after looking for help online – others have had similar difficulty. I had to mess with it for a long time trying to get fingers and other tools in there to get those two odd clips free. I wish you luck!
Unlike the A pillar covers, the overhead console should not just be pulled off forcefully. The side closest to the windshield is hinged. You have to open it from the front side, towards the seats. The two clips in front that hold it in place can easily break – I broke one and had to repair it. (I used crazy glue and a bit of metal as a splint to give it strength again.)
One surprise during the installation was finding that the Amp Research powered step installation had taken over the OBDII port completely. This port is also needed for the iDataLink Maestro. I was able to get around this with an inexpensive splitter cable for the OBD connection and it’s working fine.
While installing the Kenwood receiver/navigation system, I also chose to put in a forward-looking Kenwood dash camera. The Kenwood DRV-N250 provides 3 Megapixel recording with high dynamic range and includes a number of additional features like collision warning, parking recording/monitoring, GPS integration and auto-save on sudden motion. Most helpful though is that the unit integrates into the radio/navigation system display.
I mounted it about where the rear view mirror would be and ran its cable (along with the receiver’s microphone, see description above) along the top of the windshield behind the overhead cover, down the A-pillar behind the air bag and under the top of the dash to the radio/nav system location. One tip on doing this: remove the cover on the top of the dashboard in front of the steering wheel for easy access to threading these cables. It’s an easier and shorter path then going down under the steering column and back up again.
|Not surprisingly, the factory speakers that come with these base radio/receiver units are very basic and sound correspondingly terrible. A speaker upgrade was definitely needed.
Crutchfield has a slick new system for previewing the sound of car speakers using one of a number of known headphone sets. I don’t know how accurate it performs but it definitely let me hear differences and helped me to choose one set of component speakers among many possible options – and I’m happy with the end result. I went with these Focal 6.5″ component speakers which had the added promise of being able to fit into the factory speaker locations without too much trouble. However, the speaker installation and wiring ended up being the biggest hassle of all.
The factory configuration puts a tweeter in each of the two A pillars and a woofer down low in the door panels. These are wired together at points deep inside the dashboard that are pretty darn inconvenient. To install a decent pair of component speakers (with separate tweeters and woofers) you’ll need to change the wiring somewhat.
One option is to use the existing wire run to the woofer in the door panel, connect the crossover here and mount it on the door panel and then run the wires to the tweeter back through the wire channel and pin connectors through the door jamb and up to the A-pillar. (This is what the folks at FarOutRide did.) I wasn’t keen on messing with that door jamb connector and drilling it open, and besides (darn it), there are already wires running to the tweeters!
I couldn’t find anybody on the web who had located where the tweeter wires were spliced into the wires leading back to the receiver, but I was determined to do so. It took a little bit more removal of dashboard pieces on the passenger side, but sure enough I was able to locate the splice point buried in a friction tape-wrapped bundle of wires just to the right and behind the glove box. There’s plenty of room to mount the crossover in there. There wasn’t really enough room in there for my hands to do normal wire crimping, but these fantastic Posi-Twist or Posi-Lock wire connectors worked well in that tight space. (Amazon paid links)
The driver side splice point proved even more difficult to locate and eventually impossible to actually reach. I found it, way up behind the dashboard against the firewall but there’s no way of getting to it without completely disassembling the dashboard – which I wasn’t going to do. Instead, I decided to install the driver side crossover behind the receiver itself, connecting the factory wire run to the driver side woofer as is and running a new set of wires for the driver side tweeter under the top of the dashboard (following the same path as the microphone and dash cam wires described above).
This is what I would recommend as easiest to do: mount the crossovers behind the receiver in the center of the dash using the existing wiring for the woofers and then run two new sets of wires to the tweeters from the crossovers, routing them just under and through the dash.
After wiring, the Focal RSE-165 tweeters can simply be slipped into the factory openings in the A pillar cover and secured with some friction tape.
As I described during the radio receiver upgrade, removing the A pillar covers takes mostly a lot of force but the driver side was extremely difficult to fully release because two of the clips are unlike all the others and seem to be designed to not be able to be removed once clipped. I don’t have any advice here even after looking for help online – others have had similar difficulty. I had to mess with it for a long time trying to get fingers and other tools in there to get those two odd clips free. I wish you luck!
The next bit of trouble came from fitting the woofers into the door panels. The Crutchfield-supplied speaker adapters are just a lot of trouble. They don’t fit as is and I had to shave off a bunch of plastic bits and then find some different screws and then cut the tips off those screws to get them just the right length so as not to dig into the door frame. I eventually got them installed but screw all that. Use these speaker adapters from Hein instead (impactproducts on eBay) which are specifically fashioned for our Transit vans. I’m sure they’ll work great, just as their other adapters did for my old Sprinter-based RV.
Van Haus Conversions had already applied sound deadening material around the van, including to the cab doors. However, we had some leftover Thinsulate insulation from my speaker installation years ago on the Sprinter-based RV, so we decided we might as well use up the rest of it here on the inside of the door panels. The idea is just to reduce road noise and resonance through the cab doors and it probably helps a bit with insulating from heat and cold.
For the insulation, it’s just a matter of cutting it to fit the removable door panel and spraying adhesive before pressing it in place:
For instructions on how to apply the sound deadening material, refer to my write-up on our Sprinter-based RV.
- 3M Thinsulate SM400L automotive insulation
- Noico heavy barrel roller (one form of sound deadening material)
- 3M Hi-Strength 90 spray adhesive (for the insulation), this stuff is great!
- 3M foil tape (for covering cracks, edges and seams of the deadener material)
- an automotive panel removal tool (plastic/nylon tool with a thin leading edge to pry off panels)
- work gloves (the aluminum edges of the deadener material are sharp)
This one-piece all weather floor mat from WeatherTech works well and fits well in the cab area.
While I opted for no windows in the rear cargo doors to provide better insulation from the sun and the cold, we did have large windows added to both sides up front around the gallery area and much smaller bunk windows in the rear along the bed.
Both the front and rear windows are awning style windows from CR Laurence. While they don’t open very far and probably don’t provide as much ventilation as slider windows, they can be left open in the rain and they’re more secure from forced entry. The amount of ventilation isn’t really a problem though since the MaxxAir fan in the roof can push or pull enormous amounts of air through even just a single partially opened window – and of course we can open the sliding door and cargo doors if we want things to be very open to the air.
- CR Laurence Transit Driver Side Forward Window
- CR Laurence Transit Passenger Side Forward Window
- CR Laurence Universal Non-Contoured Awning Window
One issue with the front split pane awning windows that I wasn’t aware of when we decided to go with them is that the passenger side only has one of the two panels that can be opened. This was apparently done because the Transit has an old-style door pull lock immediately below the window. This is unfortunate as I’d prefer that they both could be opened even if it means you would not be able to leave one of them open if you wanted to securely lock the van. However, the Transit’s door pull lock is really hard to grip and pull up to unlock because of the installed window anyway!
Another issue we noticed right away with these CR Laurence windows is that the front windows have very poorly sized bug screens. All three of the panes that can open have screens that leave a large gap on either one side or the other of the frame. This would be quite the nuisance when parked somewhere warm that’s filled with no-see-ums, gnats or mosquitoes – as we’ve certainly encountered in previous travels. I was able to fix this with some black window insulation but I think it’s ridiculous that CR Laurence doesn’t make their bug screens fit properly to their windows.
I decided to go with a waterless/”composting” toilet mounted out-of-sight under a bench seat. I was originally looking at the Nature’s Head just because it’s so commonly reviewed and referenced by others. (There are also models from Air Head, Separett and Sun-Mar.) We ended up with the C-Head toilet because even its standard basic model was short enough (18″) to fit under a bench seat. The C-Head is probably the simplest design of them all and it’s crafted almost entirely from readily available hardware store parts. I got the “Basic C-Head” in matte white with the “slow close white” lid/seat and the add-on “P-tank” container which is recommended for off-road travel.
Like all of these urine-diverting toilets, the separation of urine and solid waste prevents the creation of nasty sewage and odors. And unlike the common cassette-style toilets, you don’t have a nasty tank of sewage to pour out somewhere. The solid waste is mixed with a medium like aspen wood shavings (as you would find at a pet store for small animal bedding) to absorb moisture, control odor and start the composting process. Urine is collected in a separate container. Here’s C-Head’s frequently-asked-questions page for more detailed explanations.
The C-Head being only 18″ tall allowed for it to be easily hidden within a small bench seat which ends up 21″ tall including its cushion:
This is a direct carry over from our experience with the LTV Unity RV:
I was looking at a number of mountable weather/temp sensors when I stumbled on the SensorPush Wireless Thermometer/Hygrometer. You drop these little guys wherever you’d like to monitor temp or humidity and they collect data over time and automatically sync to your smartphone via bluetooth. Unlike typical wireless weather sensors, you can view the accumulated data over time and set alerts to be notified if the temperature or humidity moves outside of a set range. They can run on their little CR2477 batteries for over a year.
I’ve got one in the van to be sure that the temperature never gets out of hand when we have the cats on board and another in the fridge to be sure its keeping things cold enough. With the RV, I could monitor them even from across a parking lot and inside a restaurant but unfortunately with the metal-walled van, the signal doesn’t travel quite so far. However, you can also get an optional SensorPush G1 Wifi gateway to monitor the sensors from anywhere over the internet. I have a couple at the Tahoe house to monitor it while we’re away and know that the pipes aren’t going to freeze. For the van, that would mean setting up a cellular internet connection and Wifi router, which I haven’t felt the need to do.
I installed a weBoost Drive X cellular booster in the Transit van. A cellular booster acts as a relay between cellular devices in your vehicle and any accessible cell towers, boosting your available signal in places where you may have little or no signal.
The weBoost comes with a small external antenna that you mount outside, either on a metal roof or on a small sheet of metal (that acts as a ground plane), and an internal antenna that you mount near wherever you’ll be using your cellular device. I asked Van Haus to provide a couple of 12V power ports (as well as a couple of dedicated USB ports) in the smallest overhead cabinet over the galley and also mount the external antenna on the roof and run it to this cabinet, where I then installed the weBoost. (I actually had Van Haus to install two external antennas in case I ever want to use a cellular modem like the NetGear LB1120 to provide dedicated WiFi in the van.)
The weBoost Drive X instructions say you should mount the internal antenna to between 18″ and 36″ away from your device. For now, I’ve got it mounted in the overhead cabinet over the cab area. With the older model (weBoost Drive 4G-X) in the LTV Unity, I had trouble getting it to perform well until I followed some online advice and started placing my phone directly in contact with the internal antenna. I then use the phone’s shared hotspot for other devices in the van, like my iPad or MacBook. I haven’t had an opportunity to test this newer weBoost model, but I’m prepared to do the same if necessary. I’ll update this once I’ve experienced using it in a low signal location. These boosters aren’t useful (and can even be problematic) when you already have a good signal.
I should add here that I’ve found Verizon to have the most coverage in very remote and rural areas across the western United States.
Here’s a video walk-through of how we’ve made use of the limited space:
Here’s the garage area before and after fully loading:
That’s two mountain bikes and all of our biking gear, an inflatable two-person kayak plus paddles, vests and assorted kayak gear, a not small telescope (8″ Schmidt-Cassegrain type) with mount, tripod, eyepieces and other astronomy gear, my camera gear, lenses and tripod, folding chairs and table, shoes and boots, portable grill, portable solar panel, water supply hoses, leveling blocks, tool box and repair supplies, tow strap, jumper cables, air compressor, extra cat litter plus a sealable bucket for used litter and of course the cat apartment itself: one room for the litter box and another for the feeding area.
This is a carry over from my old Sprinter-based RV and the issues I had with rodents causing trouble and damage in the engine compartment and utility bay. I live in an area surrounded by fields and forest and an endless supply of mice and other rodents. I tried all the usual remedies from scented sprays and herb bags, dryer sheets, noise makers, etc and still kept having trouble.
The ultimate solution I eventually arrived at was installing a walled rodent barrier around the whole vehicle, plus a Wi-Fi enabled trap as a fail-safe. It’s called the “BoxKat”. It’s a flexible/collapsible barrier for keeping rodents out of a given area (like your car or RV). It’s a little expensive but it actually seems to work – as in, I never find evidence of mice or other rodents in the engine compartment.
I did have a little trouble getting it to sit flush against the ground and not have any gaps in an area that isn’t perfectly flat due to underlying tree roots lifting up the asphalt. I also had to take BoxKat inventor Tom Sharp’s recommendation to buy some steel rods and then I still had to add some hollow concrete blocks to get the pieces of the barrier to stay in place with the extreme gusts of wind I get around my hilltop home.
I also have an electronic WiFi-enabled rat trap (from Victor) in the engine compartment to make sure that if anything ever does get past the barrier, it won’t be likely to do any damage. These are great traps in that they connect to your WiFi network and notify you if the trap is ever triggered so that you don’t have to make a point of regularly checking on them.
Anyway, the upshot is that this system of a physical rodent barrier around the whole vehicle with a trap as a backup has been working. The few times I caught anything in the trap was during actual trips outside the barrier and during times when the barrier was disturbed before I secured things down with the rods and blocks.