Messed with trailer harness - no tail lights/dash illumination

[HeadacheManNYC]

The title sums it up, but heres the whole story:

While having a full Bosal exhaust put in today, I asked the shop to "get rid of" the wiring going to a very rusted out trailer harness on the tow hitch. It seems they got rid of some, but not all of the wiring, as there is still a small mass of wires hanging down from the rear X member. They also cut a number of wires running to the brake controller below the dash. As you may be able to tell, I am an electrical moron, and was too happy with new exhaust to think twice about the wire business. Driving home, I realized I had no dash illumination, and no tail lights. Everything else works, including brake lights and secondary dash lights eg. warning lights, gear indicator. Changed the tail light fuse, and it blew immediately. Not sure what the dash illumination runs off of, but the "gauge" fuse is fine.

Sorry for the ramble and the crappy pics. Its been a long, expensive day.

Any ideas?

 

[thisbugger]

Have you checked your fuse? The trailer harness is just tapped into the brake lights, signal, etc.

 

[93Chewbacca]

Where is this picture taken? For starters, I would make sure you locate all the wires they cut and make sure none of them are twisted together (it looks like some of these wires are twisted together).

I would make sure any cut wires are separated from each other (maybe tape them with electrical tape temporarily).

Then I would try installing a new fuse and see what happens. Update us with results.

 

[93Chewbacca]

You might need some of these later on...

 

[HeadacheManNYC]

Sorry for not clarifying, the wires in the picture are hanging down between the middle of of the rear cross member and spare tire.
Initially there was a larger red wire which is now gone. When I asked the mechanic about the remaining ones he said they had been disconnected which is clearly not the case.

Which fuse connects to the dash illumination?

 

[Rwhat]

Sorry for not clarifying, the wires in the picture are hanging down between the middle of of the rear cross member and spare tire.
Initially there was a larger red wire which is now gone. When I asked the mechanic about the remaining ones he said they had been disconnected which is clearly not the case.

Which fuse connects to the dash illumination?

The same fuse for the tail lights. Your wires need to be completely removed or capped. They are still getting 12V+ and its probably grounding out. Look for splices installed in your tail lights unless its tapped into your original trailer wiring.

DJsixbillion had a similar post on Saturday

 

[HeadacheManNYC]

The same fuse for the tail lights. Your wires need to be completely removed or capped. They are still getting 12V+ and its probably grounding out. Look for splices installed in your tail lights unless its tapped into your original trailer wiring.

DJsixbillion had a similar post on Saturday

Good to know. Thanks for the replies all.

 

[93Chewbacca]

Sorry for not clarifying, the wires in the picture are hanging down between the middle of of the rear cross member and spare tire.
Initially there was a larger red wire which is now gone. When I asked the mechanic about the remaining ones he said they had been disconnected which is clearly not the case.

Which fuse connects to the dash illumination?

The larger red one was probably from the trailer brake controller in your first photo.

The rest should be traced back to their origin and make sure that they are in good shape and are not cut/spliced together and that sort of thing.

Each of those 4 wires (white, green, yellow, brown) should be separately terminated with an insulated terminator of some sort (to prevent shorts and corrosion).

I'm not sure which fuse is for the dash illumination (someone will probably chime in with that) but you should probably get yourself a circuit tester if you don't already have one (see attached photo) and test each side of the fuses in the panel to see which one has failed. If a fuse is bad the light will come on on one side of the fuse but not the other. This cheap tool also comes in hand with other basic 12V testing.

In your picture it looks like the brown wire is twisted together with another wire (back by the spare) this may explain why the tail light fuse blows immediately after replacement.

FYI:
White wire = ground
Green wire = RH turn signal/brake
Yellow wire = LH turn signal/brake
Brown wire = running lights/regular tail lamps that illuminate when you turn on the headlamp switch

 

[NorCalDoug]

you totally blew a fuse.
had that happen to me on a drive home from a trip a few years back...don't recall which one...whether it's in the fuse box in the cabin or the one under the hood...

 

[93Chewbacca]

Any luck yet?

 

[HeadacheManNYC]

Solved. The stray wires were shorting out against each other and the rear X member. Taped them off good, replaced the fuse and no problems. I'll deal with them more definitively when I get the time.
Thanks for the advice, all.

 

[xjaz]

I'm dealing with this same problem right now. My wires hung below my trailer hitch, and I smashed them between the hitch and multiple rocks several times, which caused them to short (I'm assuming). I lost my tail lights and dash lights, but brake lights, blinker lights on the dash, etc. all still work. The 15 amp fuse for that circuit keeps blowing. I cut off the smashed portions of the hitch wiring and taped off the ends of the remaining wires, but it did not solve the problem. I'll check it out tomorrow in the daylight. Any other possible remedies?

 

[NorCalDoug]

start with where you cut the trailer wires and track them back up into the cargo area. In mine, they routed up through the...hmmm...I don't recall if it's the left or right quarter panel...but it was one of those.

you most likely have bare wire somewhere coming in contact with metal...which is causing the short.