As I briefly mentioned, yesterday I installed my extra electrics for the camper trailer. I'll go through what I did in case it helps someone else. Basically, I needed to wire my P3 brake controller and put an Anderson(or 3) at the rear of the vehicle.
Warning... this is long. Prepare to get bored.
The first step, was finding a neat way to run all of the cables
I started my approach in a probing fashion to figure out the most efficient way to do the install. I started in the boot, took out the floor, including the gap hider and scuff plate. Next was the "load floor bin" I undid the two rear nuts but when I came to the front "screws" I found out that the trim removal guide was wrong, they were not screws but bolts with tiny nuts underneath that were really fiddly to touch, just above the QL tank. I decided that if I tried to remove these, it would be easy to loose the nuts and especially hard to get back together again.I figured out at this point that the load floor bin had quite a bit of flex and I could tilt it up quite steeply.
I started the steps to remove the D pillar trim but it also looked to be quite hard and also depended on having the load floor bin out. Instead I decided to try finding a nice place to feed the cables through. First I removed some of the trim around near the rear drivers side door. I always keep on hand some plastic "tongues " that were left over from some MDF panels when we renovated the house. Basically, they are a few metres long by about 4mm x 12mm. I managed to poke them through behind the quarter panel to come out behind said door. I then fed the strip down through a nice crevice below the carpet till I got to the B pillar(the one between front and rear seats). At this point, I taped my cables to the plastic strip and pulled them through. At this point, I was pulling through 2 x 8G (Power and Ground for the Anderson's) and a twin core 6mm for the Brake controller(1 for the brake line and another for the stop signal, sure 6mm is overkill for the stop signal).
From the B piller, it was easy to shoot the 2 8G cables through to the battery box as well as another twin 6mm for brake controller power. This left me with 2 twin 6mm cables to get to the front. Here it must have taken me about 30-40 minutes to get my plastic strip fed through under the plastic sub-floor from the B pillar to the A pillar, it might be easier just to put it under the carpet. It wasn't easy to lift up any of the subfloor, especially near the front of the drivers seat. I assume you need to remove the seat first. Anyhow, I finally got it through and was able to pull my cables through, from there it was fairly easy feeding them up behind the dash. I found that at the top of the media bay, there is a kind of duct between it and the instruments above. By half closing the media bay door, I was able to stick my plastic strip in above the door, down the crevice until it came out above the park brake. I drew my cables back through, routing them behind the door and was able to bring them out into the media bay without a single hole. From here it was easy to solder the 4 cores to the P3 cable, remembering their crappy colour code... Black for 12+, really.
For connection to the battery, I had two circuit breakers, I mounted them both to a timber board to wedge against the battery as I saw mentioned earlier. 1 Breaker for the Andersons and another for the brake controller.
For the Anderson connectors, things got a little more complex, well, more complex than my Subie. In my Subie, the Anderson at the rear is permanent power, just protected by a breaker. I've got a CTek D250S Solar+alternator DC-DC charger in the camper. It's alternator input has a 13.somthing threshold to activate only when the engine is running. Of course, in the GC, the variable alternator means that the voltage may be lower even when the engine is running. The solution here is to use the "solar" input of the D250S which does not have the voltage check. Problem is, I don't want to flatten the GC battery running the fridge and charging the camper while the engine is not running. Simple solution is to put a relay in the boot. I decided to also put 2 anderson connectors in the boot itself, one permanent and one switched.
Only issue with this, is getting to a switched 12v signal wire. I've heard the cig lighter being used but that's not ideal because it comes on with accessories, I want to to come on only when the engine is running, or at least while the ignition is on. Also, I didn't know how to get to the cig lighter without pulling all of the trim off. Oh, and there would be a problem if I ever wanted to move the fuse to have the cig powered permanently, though there is always my permanent anderson. The solution came to me as the spotlight dock! I checked and it is (as is optimal for charging the spotlight) switched with ignition! Here came the feed for my relay!
Anyhow, I tested it all today and everything is working fine. Except someone forgot to tell the GC that it's towing a thousand kg of camper trailer and it's supposed to go more slowly, silly car
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