We’ve Seen The (Sun)Light

We’ve done a lot of camping in our trailer over the last few years, and recently decided we wanted the ability to dry camp in places that didn’t have electricity or water.  Although I upgraded the interior lights in the trailer to LED’s last year and downgraded our electric jack to a simpler hand-crank model, I still had concerns that our basic deep cycle battery from Walmart wouldn’t run the water pump and propane-powered fridge more than a couple days.  In addition, even if we could run everything for a weekend, without access to 110V power at our parking spot back home, how would we recharge the battery for the next trip?  After reading a number of blogs from full-time RVers, solar recharging seemed like the answer.

Like every new project, I ended up spending far too much time researching my options and planning the solution.  In our case, due to a combination of expected electrical draw and available roof space on our trailer, I decided on a 200 Watt setup using low profile, flexible solar panels.  The entire installation cost about $600 and took me about 8 hours, though admittedly the first 2 were spent measuring the roof over and over before I drilled the single hole in it to run the power from the roof to the interior.



First I laid out the panels on the roof in an effort to find a location where roof vents or accessories wouldn’t cast any shadows (since even a small shadow can significantly reduce the amount of power produced).  Because I needed the connectors for both panels to use the same run down the interior and to the charging controller, to get the wires close enough I ended up mounting one panel at a 45 degree angle across the roof.


After measuring probably 50 times, I drilled two 1/4″ holes in the roof and ran the 8AWG wire through the cable feed and down the interior wall between the bunk beds and the bathroom.  Unfortunately for me there was a 2×2 horizontally inside the wall, so I ended up removing the trim and wall in order to get the wire out (which sounds scarier than it actually was).  I ran the wire under the top bunk along the wall, and then down into the front pass-through storage area, covering the run with the plastic split wire loom wherever it was exposed.

I ran about 15′ of wire from the solar panels to a 40A breaker in the storage area.  This protects the charge controller from overload, and as an added bonus allows me to disconnect power from the panels to the controller or rest of the system instantly.  Since the panels deliver voltage whenever the sun is full, this will allow me to work on the system in the future without getting shocked or climbing on the roof to cover the panels.  From the charge controller I drilled a hole in the floor and ran the remaining 10′ of wire from the controller to the battery, covering it in wire loom and securing it to the frame of the trailer wherever possible.  Once secured I filled the hole from the bottom with a healthy dose of Dicor and then covered any exposed runs of wire in the storage area with wire loom as well.  I crimped 5/16″ lugs onto all ends except the roof, and made two <6″ runs to connect the circuit breakers to the charge controller.

Finally, I climbed up on top of the trailer to mount and connect the panels.  With the panels laid out I verified that the wire length with Y connectors was sufficient, but because it was sunny I didn’t connect the panels yet.  Instead I cut the ends off the single connector side of the Y connector, then stripped and butt-spliced the 8AWG wire to the Y connector and then connected the ends of the Y to the panels.  I applied 3M VHB (very high bond) tape to the back of the panels and the cable feed-through and stuck them to the roof, then cut lengths of Eternabond and fully secured the panels and all wires to the roof and used Dicor to seal the cable feed-though.


Now assembled, I flipped the circuit breakers to “On” and within 1-2 seconds the charge controller detected the battery voltage and began charging.  I adjusted the default charge cut-off (bulk stage) from 13.8V, which is far too low, to 14.8V (according to Renogy, I should charge my flooded deep cycle battery at 14.6V (bulk) and 13.8V (float)).  At 14.8V, the charge controller will run the bulk phase to the battery at 14.8V and then the float phase at 93% of that (13.76V).  With an 8AWG wire that’s 10′ in length the actual voltage delivered to the battery is 14.66V and 13.62V, respectively.  I’ll have to monitor my battery levels to make sure I don’t cook the water off the cells, but at least the math works.


Lessons Learned

Now that I’ve had a little time to reflect on my installation I realize there are a few things I would do differently in the future, or might change about my current setup:

  1. The circuit breaker for the battery should really be as close to the battery as possible, so that if the wire ever shorts the circuit breaker will trip before the break, not after it.  I may move this in the future since the circuit breakers are supposedly waterproof.
  2. While I was able to get a decent crimp, I should have opted for a more expensive crimper and lugs (and possibly 6AWG wire).  Even though the lugs are crimped tight to the wire and the wire is stranded, I suspect I’m getting some loss at each one.
  3. To fully charge a battery, you need to apply a bulk charge of 14.4 to 14.8V for several hours, then reduce the voltage to 13.5-13.8V and maintain the float charge at that level.  The precise voltage depends in part on the battery type.  In hindsight I should have purchased a better MPPT charge controller which allows separate adjustment to the bulk and float stages, has an automatic equalize (overcharge) mode to desulfate the battery plates, and because it’s MPPT has a higher efficiency (which is best for northern climates that don’t get tons of full sun hours).  My WindyNation P30L controller has a single “Over Voltage” setting point at which it shuts off (13.8V by default).  According to WindyNation, this is the “bulk charge” limit and the “float charge” is fixed at 93% of this value.  Thus to get a 13.5V float I have to set the bulk charge at 14.6V.
  4. I was originally concerned with significant voltage drops in smaller gauge wire, so I bought 8AWG, which allows me to run 20A @ 16′ with no more than 3% voltage loss.  However with only two 100W panels I’m not going to exceed 12A.  In reality 10AWG wire would have been cheaper and I believe there are even pre-wired MC4 cable lengths available up to 10AWG.

So far I’m very happy with my setup.  And while it’s not sufficient for a full-time RVer who wants to run their A/C in the summer or watch TV in the winter, it gives us so many additional camping options, even allowing us to use more secluded non-electric sites at state parks.

Towing with a 200-series Toyota Land Cruiser

I’ve read a number of different thoughts and opinions about towing with the 200-series Toyota Land Cruiser.  One popular opinion which seems to come mostly from owners of full size diesel pickups, is that due to the relatively short 112″ wheelbase, the Land Cruiser is a poor towing vehicle.  After a few trips and tweaks to my setup, I can confidently say that with the proper setup, the Land Cruiser is actually a great towing vehicle.

Keep in mind everyone’s trailer and towing setup will be a bit different, so rather than take my setup as the bible I recommend you try out your setup and make small adjustments until you’re happy with it.


The Vehicles

My basic setup is a US-spec 2013 Toyota Land Cruiser with the 3UR-FE 5.7L V-8 engine, rated to tow 8,500 lbs with an 850 lb maximum tongue weight, and a 2005 Forest River Surveyor 235RS trailer which weighs about 5,000 lbs and has a roughly 600 lb tongue weight when loaded with all of our gear (except fresh water).  Prior to the Land Cruiser we towed with a 2008 Acura MDX with 5,000 lb rated tow capacity, which definitely pushed the limits of that vehicle.  Aside from the trailer, when camping we have 2 adults, 3 kids, a 75lb dog, a cooler full of food and ice, as well as clothing and other miscellaneous items in the vehicle (easily 650-700lbs).


Weight Distribution

One of the keys to the proper towing setup is a good weight distributing hitch with anti-sway setup.  When I purchased the trailer I brought it home using a basic hitch and standard 2 5/16″ hitch ball.  When I got home I immediately ordered a Pro Series Weight Distribution Hitch with Sway Control for about $250 from eTrailer.com. (Note: Because I never expected my tongue weight to exceed 500 lbs I purchased the basic PS49901 model, with a 550lb limit.  While I’ve considered upgrading the bars to allow me to shift more weight and better level the vehicle, the heavier bars tend to make the ride stiff and bouncy).  When engaged, the weight distribution (WD) hitch and trunnion bars transfer a portion of the tongue weight off the rear axle onto the front axle of the vehicle.  I once weighed the Acura at a truck stop with and without WD and the setup did shift about 80-100 lbs to the front axle depending on how many links on the chain were pulled up.


When I moved the Pro Series WD setup to the Land Cruiser, I discovered that the trailer was not level (nose-up by several inches).  While most trailer hitches are level at 21-24″, the Surveyor frame sits about 6″ lower to the ground.  Thus even at the lowest setting, the hitch ball was at least 4″ too high.  When combined with less tongue weight (one empty 30# propane cylinder and no bicycles stored in front), the trailer felt squirrel-y on the highway whenever there was a gust of wind.  To get the trailer level when towing, I ended up purchasing a taller weight distribution hitch bar (shank) from Amazon for $75, which allowed me to drop the height of the hitch ball several inches lower.  For my setup, I purchased a Curt 17123 (which is actually 12.25″ tall) with the WD hitch mounted at the lowest setting makes the trailer almost perfectly level after my last modification.

Helper Air Bags

While the WD hitch does a solid job, I carry varying loads at times depending on whether we bring all 5 bicycles, how much propane is in the tanks, etc.  I considered using a heavier duty WD setup, but the stiffer bars have a lower limit of 550 lbs which could present handling issues when running a lower tongue weight.  In addition, it’s recommended that 8 to 15% of your trailer weight be located on the tongue, and with a 5,000 lb trailer I was concerned about shifting too much weight off the tongue and onto the front axle as trailer sway, especially as caused by tractor trailers at highway speed, can be a serious problem.  Rather than change to stiffer WD bars, I realized I needed to do something to better support or strengthen the rear suspension.  That left me with two options:

  1. Upgrade the rear springs from standard to heavy duty (340lbf/in) or more.  While this would limit compression (and thus the rear end sag) when towing, the stiffer springs would almost certainly make the rear end quite bouncy when unloaded.  As the majority of our non-towing driving is on city streets loaded with potholes, I was afraid any upgrade would completely ruin the ride of the vehicle.
  2. Install a set of helper air bags inside the springs and inflate them when towing.  This has the benefit of allowing adjusting the stiffness depending on the situation by adding or removing air from the bags.

I ended up opting for the helper air bags and purchased a Firestone 4164 air bag kit and a standard duty Air Lift 25804 air compressor from Amazon for under $250 and documented the installation here.  I’ll summarize that article with the following quote:

With 35psi in the bags, the Land Cruiser towed like a friggin’ champ.  The ride was very smooth, and with the anti-sway bar installed I had no trouble running 70+mph on the highway.  All in all I’m very pleased with the setup.

Sway Control

The Pro Series Weight Distribution Hitch I ordered comes with a friction anti-sway device (available separately for $40).  It basically sandwiches a piece of metal between two other pieces which you compress by tightening a bolt on the device.  If you’re towing anything more than a pop-up at 45mph or higher, you really want one of these.  The device takes less than 60 seconds to install or remove, but does a great job of limiting swaying in crosswinds or when passing tractor trailers on the highway.


The Land Cruiser comes with a trailer brake controller port, but if you’re towing a trailer with a GVWR > 3,000lbs, you’ll need to order and install a controller and wiring adapter.  I purchased a Tekonsha Primus IQ a few years back for  the Acura, so I just needed to order the Tekonsha Toyota Wiring Harness.  Installation took about 30 minutes by following the Trailer Brake Controller Connector discussion over at iH8mud.  I mounted mine at the bottom of the dash on the left side – out of the way, but requires me to lean forward to adjust it.  My biggest complaint with the Primus IQ is that I feel like I’m always fiddling with it to get the braking proportion just right, which sometimes leaves me locking up the rear tires at low speeds.


The last upgrade I made (and highly recommend) was to purchase an ELM327-compatible Wi-Fi OBDII reader ($15-20) and the EngineLink App for iOS ($6).  When towing I insert the reader into the OBDII port and connect my iPhone to the CLKDevices WiFi name, then fire up EngineLink.  Based on a number of other threads I read, I added two additional gauges in order to be able to monitor the automatic transmission pan and torque converter temperatures while towing:

  • Toyota A/T Pan Temp. PID 2182. Formula ((((A*256+B)*(7/100)-400)/10). Range -40 to 300. Units are F.
  • Toyota A/T TC Temp. PID 2182. Formula ((((C*256+D)*(7/100)-400)/10). Range -40 to 300. Units are F.





Because the Land Cruiser is over-built, there’s no need to add a separate auxiliary transmission cooler.  However, when towing you should always put the vehicle into “Sport” mode by pushing the shift lever to the left.  The “Sport” (or manual shift) mode limits the vehicle to no higher than 4th gear unless you manually select 5 or 6.  This is Toyota’s recommendation as well.

Based on my own monitoring of transmission temperatures, 4th gear (which is 1.000:1) minimized torque converter spin and significantly reduces heat.  I wrote about my experience in this posting at iH8mud:

Limiting the vehicle to 4th gear I was cruising at 65-70 in mostly flat Illinois/Wisconsin (I-94) and ran around 2800RPMs +/-. I got ~10.5MPG at that speed (the instantaneous MPG reading from OBD2 was pretty steady between 10.2 and 10.8MPG). I tried running in 5th for a while but I found I had to lay into the gas pedal more to keep it at 65, so my gas mileage actually went down. Unless I was driving 55, using OD provided no MPG benefit.

I also watched the temps closely during the trip. Outside it was ~65F out. Intake temp was reading about ~90F (typical). My trailer was at the shop getting the bearings repacked so I drove about an hour to pick it up and then about an hour after I hitched up, thus I got some great comparison #’s:

  • Without a trailer running in top gear (6th) the transmission pan temp reached 195F (+/- 1F degree), and the torque converter was anywhere from 195F (when fully locked) to about 208F (for instance when accelerating from 60-70). The higher TC temp didn’t affect the pan temp much. Once the TC locked up again at ~70MPH the temps would both stablilze around 195F again.
  • With the trailer running in 4th gear the pan temp stayed around 196F (+/-1F). Both the TC and the pan temp would read the same when cruising at 65MPH. About 2/3 of the way through the trip I tried running in 5th gear (first OD). The TC temp would climb (at one point it hit 213F) and the pan slowly climbed up to about 202F over the span of about 5 minutes before I put it back in 4th. At that point the temps slowly dropped down to 195F again. Also, I definitely noticed the weight of the trailer a LOT more when towing in 5th than in 4th.

In short, don’t tow in overdrive – the gas mileage difference is small and OD generates heat in the transmission, especially if the ambient temps are warmer and/or you’re pulling through hilly terrain. Yes if you’re pulling a 2000# 4x5x8 uhaul trailer you can probably run in 5th or 6th without any damage, but if you’re pulling a smaller trailer running in your 1:1 gear (6th in your case) will have less impact on your MPG than it does for me, so the $ savings is minimal.

I had a second opportunity to confirm my temps this weekend when the outside ambient temperature was 86F and got nearly identical results.  At 70mph on the highway the engine temp read 194F and both the pan and torque converter on the automatic transmission read 198.5F.

I understand the “A/T Temp” warning light will come on at 302F, though I hope to never confirm that.

Last Thoughts

With the proper setup (weight distribution, anti-sway, and upgraded rear springs or helper air bags), the 200-series Land Cruiser has no trouble towing a 24′ travel trailer weighing 5,000 lbs.  We don’t intend to upgrade our trailer, but if we did I wouldn’t hesitate to go up to ~26′ and 6,000 lbs.  While you should always follow manufacturer recommendations, I felt very comfortable cruising at 70mph and am looking forward to taking a much longer trip to Mt. Rushmore later this summer.  As I said in the air bag installation posting, the Land Cruiser towed like a friggin’ champ.


Firestone Helper Air Bag Installation

We towed our 5000 lb travel trailer with about 600 lbs of tongue weight for the first time with our 2013 Toyota Land Cruiser earlier this month, and with almost 4″ of sagging at the hitch I decided I needed to do something to level the vehicle.  While I considered stiffer springs, I didn’t want a jarring ride for the majority of the time we drive unloaded in the city.  After reading a number of posts, I decided to install a set of helper air bags in the rear.  For a non-lifted (standard height) 200-series Land Cruiser, I purchased the Firestone 4164 air bag kit and a standard duty Air Lift 25804 air compressor from Amazon.   For posterity, I thought I’d document the process here and on the iH8Mud forums.

Materials ($200-250):


Installation was pretty straightforward, as I generally followed the instructions posted at http://www.australianimages.com.au/project200/airbags.php.   Installation of the air bags took about 2 hours, though admittedly I had access to a lift and a phenomenal mechanic to help me wrench.  We did find ourselves straining to get the shock absorbers reattached and ended up using a ~5′ steel bar for added leverage to compress the rear springs better.  About the only other modifications were that we didn’t bother to disconnect any breather hoses (there was plenty of slack), we didn’t tighten the KDSS valves back down until the vehicle was on the ground and had settled a bit, and I slathered the KDSS screws with marine grease before re-tightening them.

  1. Jack up the vehicle.  Support with jack stands or use a lift if you’re lucky enough to have access.
  2. Loosen the screws on the KDSS system (located under the rear door on the driver’s side bolted inside the frame rail) 3 turns (no more!)
  3. Remove the rear tires
  4. Mark the spring, bump stop, and frame with chalk or a marker (optional but helpful)
  5. Remove the nuts from the bottom of the shock absorbers and remove the shocks from the lower mounts
  6. Remove the two bolts from each sway bar mount (left and right)
  7. Apply leverage to the rear end and remove the springs
  8. Remove the bump stops from the top of the spring.  For stock suspension, cut off 4 stops with a sawzall (leaving just the base)
  9. Put the air bag inside the spring, connector facing upwards and put the remaining flat disc part of the bump stop back on top of the spring, aligned with your marking
  10. Fish the air line through the top of the bump stop and push it firmly into the air bag.  Don’t worry, the bag’s internal compression fitting will secure it
  11. Fish the air line up through the spring mount and re-install the spring/air-bag/bump stop assembly.
  12. Push the air bag up to the top of the spring and run the air lines along the frame into the trunk compartment, ziptie-ing every 1-2′.  You’ll need to poke a small hole in the rubber grommet in the right rear in order to fish the lines into the jack storage area.  I chose to run both lines individually into the compartment and T them together there because I felt it was more easily accessible in case they leak and require replacement in the future, but you could also T the lines together underneath the vehicle and run a single line up to the compartment.
  13. Reinstall the sway bar, shocks, and tires
  14. Lower vehicle to the ground, bounce on the running boards to settle the suspension, then re-tighten the KDSS screwsThe compressor took about twice as long, though 2/3 of that time was spent trying to figure out how to mount the compressor and easily get power to it.  I wanted the compressor hidden but also safe from the elements, so we ended up removing the jack and mounting the compressor at a 30-45 degree angle in the jack compartment.  (At the moment the jack is now sitting in my trunk, though I will likely mount it under the hood in the near future as there’s lots of extra unused space).
  15. Remove the jack and retaining bracket.
  16. Determine how you will mount the compressor.  We mounted it to 2″ wide x 10.5″ long steel bar, and we drilled and bolted that to the mounting holes for the jack retaining bracket.  If I had to do this in the future I might buy and cut a piece of sheet metal and mount the compressor to that ahead of time.
  17. Mount the gauge to the body.  We used the shortest self-tapping screws we could find, since the gas filler neck is on the other side of the metal.
  18. Following the air compressor installation instructions, and using the additional union T fitting you purchased, attach all the air lines
  19. Attach the negative (black) wire to a solid ground screw
  20. Run the positive (red) wire to the engine bay.  We ran the line underneath the vehicle, though at some point in the future I will probably re-run a bundle of wire from the front to the rear through the door sills.  Either way, make sure you put the 15 Amp inline fuse inline just before you tie the compressor into the battery!
  21. Flip the switch and pressure test.

I kept any extra tubing and fittings in a quart size ziplock bag in the storage compartment, just in case.



Firestone recommends keeping a minimum of 5 psi in the air bags at all times in order to avoid pinching and damaging the air bag.  They also state the maximum pressure of the bag is 35 psi, though I had to confirm with Firestone that you should load the vehicle first, then inflate to 35psi.

  • Driving around town and on the highway with ~5 psi in the bags the ride was smooth and there was no discernible difference from stock.
  • With 5 psi in the bags and a full 1400 lb payload (2nd row folded and 35 bags of mulch completely filling the 2nd row and trunk) the rear squatted a bit but the ride was unbelievably smooth.  Keep in mind with the air bags inflated you’re basically resting on the bump stops at all times.  The air bags are much more flexible than the bump stops, so it’s a smooth transition, but if you’re under load you really should have more than 5psi in the bags to avoid over-compressing the rear end and damaging the shocks or fenders.
  • With 8-9 psi in the bags the truck feels stiffer when unloaded.  When hitting bumps on the highway that cross the entire lane, I noticed a more pronounced hop from the rear (and actually a bit from the front too, which I’m thinking is due to the KDSS).  While I’ve not driven in a Land Cruiser with upgraded (heavy duty) rear springs, I imagine the feeling is similar to a 1/2 ton vs 3/4 ton pickup.
  • I ended up running 35psi in the bags when towing.
    • With 5psi in the bags and about 200lbs of gear (and dog) in the trunk, the top of the rear end wheel well sits 21.5″ above the center of the axle.
    • Adding about 600lbs of tongue weight on the trailer, the rear end sinks to about 19.5″.
    • Setting up the weight distribution bars on the 4th link bumped it up to 20″.
    • Increasing the bags to 35psi, the rear sits at just under 21″.

One other note is that the bags gave me about 1/2″ of lift in the rear.  Since there was already about 1″ of rake front-to-rear, I may end up adding a set of 1″ front coil spacers up front in the future to better level the vehicle.  Then again, when fully loaded the vehicle is pretty level now, so I may not mess with it.

With 35psi in the bags, the Land Cruiser towed like a friggin’ champ.  The ride was very smooth, and with the anti-sway bar installed I had no trouble running 70+mph on the highway.  All in all I’m very pleased with the setup.

LC with proper towing setup