Strange Tail/Brake Light/Turning Signal Electrical Problem!

[videoguyjh]

I have a very strange issue with my '02 QX4. I've never seen anything like this before. It began a couple days ago. Here's what it happening... when i turn my parking lights or headlights on, my left turning signal and my third/high mount brake light turn on at about half power (turning signal is steady on, no flashing). When i brake with my lights on, the third/high mount brake light and the left turning signal get brighter. With my lights off, the left turning signal comes on (about half power, no flashing) when i step on the brakes. It started with just the third/high mount brake light coming on with the parking lights or headlights, and now the turning signal thing is happening. However, there are moments when this issue seems to disappear and everything works normally, but that doesn't last long.

I brought the truck to Midas and they looked at it for a while and couldn't figure it out, they were stumped. I called my local Infiniti dealer and they said it could possible be a malfunctioning bulb (as simple as that sounds). So, i took the tail lights out and removed bulbs, swapped bulbs, but it didn't help. All of the bulbs seem to be working fine.

I should also mention that the previous owner of the truck had an aftermarket Viper remote start system installed and trailer hitch wiring installed. But, I've had the truck for almost 3 years now without problems. The previous owner did mention that after he had the trailer hitch wiring installed, one of the tail lights was malfunctioning and he had to bring it to the dealer to get fixed. So I'm thinking that it may have something to do with the hitch wiring, even though I've never used it.

Has anyone ever had a similar problem? Or, does anyone know what the problem could be? I will most likely be forced to bring it to the Infiniti dealer on Thursday...and be forced to pay a hefty repair bill

HELP!!

[Towncivilian]

Check for frayed or damaged trailer wiring to start with.

[chris_clark1979]

Check you trailer wiring. Some of the wiring is straight wired, some have a little box and have factory connectors.. If you have the trailer wiring with the box and factory connectors just disconnect the wiring harness and leave the trailer wiring harness undone and see what happens. If you have the trailer harness straight wired just undo the wires and cover with electrical tape and check to see if the problem is fixed.
I neither of them fix the problem undo the alarm and check to see if that fixes it.
Let us know what happens.

[Chuck Tribolet]

The half power is a clue. There's an open connection to ground, probably for the left brake/turn signal. When you step on
the brakes, current flows through the left brake light then backwards through the left turn signal, thence to ground through
all the other turn signal lamps. The black wire coming out of the left brake/tail/turn assembly is the culprit. The problem
may be internal to the assembly, or it may be outside of it on the black wire. Unplug the assembly. Measure the resistance
between the Green with Yellow stripe wire and the back wire with the bulbs in. If the resistance is very high (megohms or
open), the bug is inside the assembly. If the resistance is kinda low (less than 1000 ohms), the problem is outside the
assembly.

The above from a 2001 FSM, but your 2002 should be the same.

Chuck

[videoguyjh]

Thanks everyone for your replies! I'm taking the truck to a friend's dad who is a mechanic within the next few days. I'll make sure he checks out the trailer wiring and the ground wiring for the tail lights. I'll keep you posted! Thanks again.

[videoguyjh]

Took the truck to my friends dad today who is a mechanic. I showed him the issue and as soon as I told him that I had trailer wiring, he knew that was the issue. He removed "U-Haul taillight converter" and the problem was solved! (The converter is used to convert the separate turn signal wire and stop wire into a single wire.) It appeared to be burned out. The wiring was melted.





I don't use my trailer hitch, except for my bike rack, but that doesn't require the wiring. So, he ripped out the box and taped off the wires. Problem solved! And the best thing is, it didn't cost me a penny! I'm just surprised Midas had no idea what the problem was, even after I told them that the previous owner had problems with the trailer wiring...very disappointing. I guess I'm not going to Trust The Midas Touch anymore!