Rear taillights not working properly.

[HoustonRV_Guy]

Have a strange issue with my coach (2014 ACE 27.1). Discovered it yesterday while getting it ready to take out this fall. So far as I know, nothing has changed since the last time I tested the rear lights.

With the headlight on, all coach lights are on correctly including taillights.

When applying brake - the reverse lights come on steady but no other rear lights.

When applying turn signals - front signals light up but no blinking (probably not enough load for relay) and no rear lights at all.

Hooked up my toad tow lights to the 7 wire trailer plug - all lights work properly.

Went hunting for fuse boxes - found one to the left of the steering column (had to become a contortionist to get to it) - nothing blown. Found the Ford chassis fuse box above the air intake - nothing blown. Found the Thor fuse box kind of off to the side in the engine compartment - harder to get to and harder to pull the fuses but nothing blown.

I'm at a loss as to what the heck happened.

Anybody have any ideas?

Shelton Smith
2014 Thor A.C.E 27.1

[JamieGeek]

Sure: Unscrew the fixtures from the rear and pull them out. I bet you'll find a lot of water back there, including some rotted wood.

The seals on the taillights aren't the best in the world.

[Hooligan2]

Previous motorhome, I had the squirrels get to my taillight wiring with similar results.

[RV Pirate]

Without further investigation, sounds like you may possibly have a bad/ weak ground or grounds somewhere. When you connect to the toad, the lights work, if I read this right. That might mean the ground in your 7 pin is making the ground connection good and your lights start working properly. Since the lights work, I wouldn't have expected a blown fuse anywhere. Try connecting a jumper wire to the ground wire coming from the problem lights and ground the jumper to the frame. (Make sure you have a good ground on frame) See if that cures the problem, Hope this helps. Good luck.

[HoustonRV_Guy]

Originally Posted by JamieGeek

Sure: Unscrew the fixtures from the rear and pull them out. I bet you'll find a lot of water back there, including some rotted wood.

The seals on the taillights aren't the best in the world.

Thanks for the reply.

Already been through this repair last year. Put some Flex Seal in the hole behind the fixtures to prevent the water damage to the exposed plywood. Luckily didn't have any water damage yet. That sealed everything up nicely so that if the gasket around the light fixture failed, no vulnerable areas would be exposed to water.

[HoustonRV_Guy]

Originally Posted by Hooligan2

Previous motorhome, I had the squirrels get to my taillight wiring with similar results.

Not sure if it was squirrels but you were right - wiring issue.

[99dart]

Wow, that would do it! If you can, I would solder the affected wires & use shrink tubing to seal them. If you can't solder them, use die-electric grease on the wires in the crimp connector.

[axis earl]

I admit that I really suck at soldering which is the right way to do it. I use the crimp connectors and then seal the ends with liquid electrical tape I purchased from West Marine. Still use the split plastic looms to protect the exposed wiring. What do you think caused that? Possibly something thrown up from the tires? Or was it the squirrels?

[HoustonRV_Guy]

This is in the rear of the coach behind the tires almost at the back bumper. I can't think of what would have done this damage other than some sort of odd road debris hit.

I'm going to remove some of the split loom to see if I can get enough slack in the individual wires to do the repairs right without having to add a jumper wire. I don't know if I can solder in the tight space but I'm going to try. Otherwise I have some heat shrink crimp butt connectors that are marine rated that work fairly well. I'll put another layer of the split loom and tie it up higher to the chassis so it won't happen again (hopefully).

[RV Pirate]

Looks like something hit it.. squirrels aren't that neat..😁