Tail light doesn't work only when headlights are turned on

A few weeks ago I found a frayed wire in the left corner light that was making my dash and tail lights go out. I patched it with some electric tape for the time being. The right tail light and my dash now function as normal but the left tail light is still having issues. The brake light works and it works when it's just daytime running lights but once I turn the headlights on it goes out. Any one know how I should go about fixing this? I already checked fuses and bulbs.

 

It is always good to share just what year you are working on.

From what you describe just the tape did not fix your problem

Was it just one wire or the whole harness this was in the left tail light housing you removed the tail light housing to see the problem ?

The wire might be so frayed it no longer can carry the load you might need to splice in a new section of wire there also might be more wires damaged

It can`t hurt to clean out the sockets I use a fitting brush and CRC-56

The brake lights should not be effected by the head light circuit at all .

 

Thanks for the reply. I'm working with a 2001. The wire seemed to have the insulation worn off and the exposed wire was making contact with the body of the truck causing a short. I got in an accident last year which required me to replace my bumper and headlights. One of the corner turn signals wasn't properly reattached when the front end was repaired so it began to rub on the body of the truck. Because it wasn't properly repaired, it was easy to pull the corner turn signal light out and see the damaged wire.

It's weird because after hearing some advice on here to check the front driver side corner turn signal lights to fix the issue of the fuse blowing from the short circuiting. It fixed the dash lights and the right tail light but not the drivers side one. When you say the brake lights should not be effected by the head light circuit at all, what would be effecting the brake lights? Are there other wires or areas I should check for damage that may be affecting the brake lights?

I think my headlights are a whole nother issue. I've had to replace their bulbs three times in the past year...

 

sounds like you may still have an exposed wire or bad ground somewhere causing the issues.

what happens when you turn on the running lights but NOT the headlight, does everything function normally? Run/brake ?

possibly bad stalk switch as it controls run and headlight?

check for corrosion at the connectors, water or salt could cause intermittent problems if there is lack of power flowing through the wires (@Bivouac mentioned carrying the load, headlight could be drawing more, leaving the frayed wire not sturdy enough to carry )

 

Headlights seeing a over voltage condition?

Just what bulbs are you buying? My headlights are always on I see no abnormal bulb replacements .

Corroded or loose headlight plugs .

 

I've spent the past 3 weeks on and off working on it and haven't resolved the issue. I'm going to have to take it in. Do y'all recommend going to the dealer for this or is there another type of shop I should look for?

 

Not the dealer in most cases a truck that old the techs are lost.Unless you already have a good relationship with your dealer.

A Shop that is known for auto electric work. Doing this work can get very expensive.

If you go this route write up a very easy to read note explaining the problem and the troubling shooting you have done the time you want to invest .

normal shop rate per hour

If you were close to me I would be glad to help.

Good luck!

 

Having the same problem, OP did you ever get it fixed? My brake light without the headlights, and parking light works fine, but once I step on the brakes with my headlights on the driver side brake light doesn't work. Don't have any wiring problems as OP did as far as I know.

 

@c808nner @ayemmus

Long shot question, but do you have trailer hitch wiring harnesses...? https://www.tacomaworld.com/threads/brake-lights-not-working.611887/page-3#post-27861586

 

Any updates or solutions found here?