Camper shell brake light issues....

[snoxxy]

Hey everybody.

I haven't been here in FOREVER. Anyway, in my absence I was deployed, returned, bought a Titan with ARE camper shell and been driving that for awhile.

So here is the problem. I was told my 3rd brake light on my ARE camper shell is flickering sometimes. So tonight I decided to really look into it, I popped out the drivers side tail light and inspected everything. First the connections the installer made were terrible and my brake light wire for my actual tail-light broke while I pulled the light assembly out. No big deal. spliced it back togther and looked at everything.
So in my camper shell I have a dome light with a on/off switch and a 3rd brake light. They were wired as follows: brake light was tapped into and a positive sent to the 3rd brake in the camper shell. Parking light was tapped into and positive sent to dome light. On the plug to disconnect the camper in case one might want to lift it off the grounds were merged on the truck side of the plug and it had a single 16 AWG ground wire. So far so good.
However when the brakes are triggered the 3rd brake light is VERY dim, until you switch the dome light on, then it gets really bright. The Dome light NEVER comes on though it has a good bulb. Even with the dome light completely disconnected from the circuit the brake light never gets very bright unless the dome light is hooked up and switched on, in which case it doesn't even work.
SO... I figured hell I will wire the dome light in with the tail gate lights, which get triggered by the interior lights. same issue. I made a seperate ground for the 3rd brake light, same issue.

Any ideas?

Sorry for the long post and hell .... I'm back

Phil

 

[sargeek]

Check the ground

Check the ground. A lot of electrical problems are associated with bad grounds.

 

[snoxxy]

checked ground, ground is good. made another regardless, also verified good with a multimeter, same issue.

 

[spencyg]

How is it grounded? How does the circuits for the brake and dome lights tie into the stock electrical system? Although I can't really envision how it could happen, it certainly sounds like you have something hooked up in series instead of parallel. Parallel wiring will provide 12V to all fixtures and will have a variable current. Series will provide a constant current to all fixtures but the voltage will be shared between those wired in series. Dim lights sound like not enough voltage. This could be ground, series wiring, or a bad connection in the hot side of the circuit. Sounds like you need to do more work with the multimeter. Verify what voltage you're actually getting across each light bulb...

 

[spencyg]

How is it grounded? How does the circuits for the brake and dome lights tie into the stock electrical system? Although I can't really envision how it could happen, it certainly sounds like you have something hooked up in series instead of parallel. Parallel wiring will provide 12V to all fixtures and will have a variable current. Series will provide a constant current to all fixtures but the voltage will be shared between those wired in series. Dim lights sound like not enough voltage. This could be ground, series wiring, or a bad connection in the hot side of the circuit. Sounds like you need to do more work with the multimeter. Verify what voltage you're actually getting across each light bulb...

 

[Sportsman Matt]

Saw that quite a few times. The ground for the brake light and the interior light are commonly shared. But sometimes the wiring gets messed up from the factory, lots of times the ground labled is the positive for the lights and the positive for the interior light is the ground, so when you switch the light on the ground is made, and dim lighting is caused by backfeeding the parking lights when the brake lights come on, but the brake lights will be very dim. Best thing is take and use a continuity meter to check the cap ground from the interior light to the wiring harness, then hook that to a good ground on the vehicle. Then do the same for the interior light and hook that up to either your parking lights or what I prefer a 12V dedicated line, usually off a 7Way plug harness so it's available anytime without having to have the truck on, but you can choose whatever you want. Then hook the brake line to either the parking brake or on some vehicles thay have a dedicated 3rd brake light line run with the trailer wiring, usually a small light blue wire.

Good luck and let us know how you make out with the lighting problem.

 

[snoxxy]

sorry ... no updates yet... been stuck a lot with work and soon to be redeploying.