Tail lights not working

soooo...anyone know where the common ground is for the tail lights? Both of my tail lights don't come on. The brake lights work, reverse and signal work just fine, just not the tail lights when I turn the headlight switch on.

In my experience of a light does not work it's usually a bad ground.

The tail light and brake light (same bulb) are an LED bulb, but that shouldn't make a difference seeing how as they have worked just fine previous to a few days ago

I've checked all the fuses ect. ect.

Any insight would be appreciated. I know I'm not the only one who's had this problem haha

 

I think the tail and brake share the same ground, so maybe it's the hot wire that's a problem if you still have brake lights.
Any excess mud hanging off the harness?
Do you still have dash lights? Front running lights?

Just for giggles, maybe try a regular bulb to see if the led fubared.
One other thing, I have led's for backup and they quit working or would work randomly. The solder bump in the housing needed to be shined up a bit and took care of the problem.

 

There's no mud in there, the truck stays pretty clean and I don't go looking for it.

I've tried switching the LED bulbs out for one another and that didn't solve the issue either. Still have dash lights and front running lights yes

 

Your front running lights, tail lights and license plate light are all fed from the same source. If everything but the tail is working, it's time to trace the wiring back from the socket until you find the break in the wire or a short. Before all that, take a tiny screwdriver or something to scratch with and shine up the solder bumps in the bulb housing, make sure that connection is good to the bulb.

Trailer wiring maybe if you have that.

 

Plug diagram for the 03 if that helps.

 

Do you have a hitch and trailer plug? Its common for these to short out internally and cause all sorts of issues with your rear lights.

 

Yea i have a trailer wiring harness but it's not plugged into anything. When I bobbed the box I capped everything and tucked it up out of the way. I'm going to trace a few wires tonight.

 

The trailer wire "box" is usually what fails, not necessarily the wiring. Try disconnecting the plug in adapters, if you have this type. If you have it soldered or tapped into the factory wiring then it's up to you.

 

Well I figured it out. I started at the wiring harness that runs along side the drivers seat under the door kick. Cut back all the tape and wire loom, then started poking the multi meter into each wire singling out each one until I had 12v with the ignition off but headlight switch on. After about 5 minutes I found the lucky green wire. Traced that wire back along side the frame rail until the gas tank. Check it there for 12v again. Still had it. So I'm moved to the split in the wiring for the tail lights. Had 12v there.

Problem was the drivers side quick dissconnect plug at the tail light. The male spade was corroded for the running light, and Toyota being Toyota, power goes in through that light, then doubles back and splits off to the passenger side.

It had nothing to do with the trailer wiring, which I figured. It's all capped with heat shrink fr when I bobbed the box.

 

My 1995 Tacoma has a trailer plug and that is most likely the culprit in my issue, no tail lights, everything else, but that and the license plate light. We checked all the fuses, replaced a couple just to be sure, and still no tail lights. I am wondering what to with the trailer light mechanism so I can fix the lights. I need the trailer lights in the summer, we live in northern Michigan and right now I need tail lights.

 

I'm going to try and revive this thread as I am having the same issue everything but my taillights are working. I had to replace my trailer light adapter a couple months ago and I just noticed the taillights are out. I imagine I need to do the same thing as OP and go along with a multi-meter till I find the short? Going to keep looking for some clarification and if I get some I'll try and link it back here if I remember.

 

check the simple first, look at the connectors at the tail lights for the trailer harness and see if they are all good looking or corroded. may need a small flat file to shine them up and put some dielectric grease in there

 

So if that's the case then shinning them up should clear up the short and putting some dielectric grease in there should prevent it from happening again?

 

that would be best case, yes. worst case you still need to track down where the issue is

 

Awesome! Thanks for the advice! Keepin' my fingers crossed for best case!

 

I had this exact problem on one of my trucks, left side tail. Inside the connector was a nasty mess and no continuity.

I think the grease that was used at that location must have been poor quality. It ended up doing the exact opposite of what is was supposed to do!

 

I opened up the trailer light adapter and there's no corrosion inside there what so ever. Got under the truck and found a couple wiring harness connectors, disconnected and reconnected those as well as tested them with a multi-meter and I seem to be getting some current at each of them. But still no tail lights.

 

bypass the trailer harness and see if the tail lights start functioning again. Process of elimination - I would always start with trailer harness and remove that from the equation

 

So I feel like an idiot... Turns out my issue was a blown taillight fuse. When I first started looking into it I had miss-read the fuse box diagram and looked at the wrong fuse. Although on the bright side I learned a lot about the wiring harness at the back of my truck! But I do want to thank @frizzman and @ThunderOne for the help!

 

glad you got it working