Tail Lights won't work..Brakes,Blinkers,Reverse does.......HELP!

[climber-420]

I have a 2004 Xtra Cab Tacoma. A friend noticed that my tail lights were out the other day. My bulbs are fine, because the blinkers work, the brake lights work, and so do the reverse, but no tail lights when my headlights are on. I know that the "License Plate" lights are on the same fuse as the tail lights. Stopped by AutoZone last night, and both License Plate lights were out. Picked up new ones, and installed in the parking lot, hoping that the tail lights would come on, and nothing. I read somewhere on TacomaWorld that the taillights would be linked up to the trailer hookup. I am just really confused about why they won't come on with my headlights, when everything else in the "group" does. Anybody have any knowledge or advice, as I do not want to go to the Dealership, and pay a ton of money for something I can fix, If I just know where to start looking. I feel like I have checked all the obvious places such as the fuse boxes, bulbs, etc.

This is not really a safe thing to have happen, and I do not wish to get pulled over.

 

[deadbeat son]

My bulbs are fine, because the blinkers work, the brake lights work, and so do the reverse, but no tail lights when my headlights are on.

I believe the lights should use a dual filament bulb, ie one filiment for tail lights, and another, brighter, filament for turn signal/brake light duties. Reverse lights should be another bulb yet. The cheap/easy test is to replace you taillight bulbs to see if that corrects the issue. If not, its time to break out a test light or DMM and get to work isolating the problem.

 

[pwr2lbs]

Have you checked for power and ground at the bulb fitting?

 

[climber-420]

I haven't checked those things because I figured that it would be ok, if the other functions were working. The license plate bulbs won't even come on, even with new bulbs in there. You think by replacing the "dual filament" bulbs in the tail lights, that it would work, and also revive the license plate ones as well?

 

[climber-420]

Deadbeat, I only see one bulb(when pulling off the cover), and turn it over. How do you get to the other bulbs without breaking that seal on there?

 

[pwr2lbs]

If they are in fact on the same circuit, then perhaps. But by checking the power and ground you can at least isolate which side of the circuit is having an issue and trace from there. There should be some youtube videos online that show proper usage of a multimeter, for the ground side you just need to test for an open/closed circuit. You can get cheap multimeters from most auto parts stores.

Best of luck

 

[deadbeat son]

Deadbeat, I only see one bulb(when pulling off the cover), and turn it over. How do you get to the other bulbs without breaking that seal on there?

Is this not what you see when you pull the housing?

Man, I would offer to lend you a hand troubleshooting tonight, but I have to get things ready for a 6:30 flight tomorrow morning with my 15 month-old daughter in tow...

 

[deadbeat son]

You think by replacing the "dual filament" bulbs in the tail lights, that it would work, and also revive the license plate ones as well?

If the tail light filament was in a circuit wired in series with the license plate bulbs, then yes. However, I don't have a schematic, so I don't know if that's the case. Sorry.

 

[washington taco]

Check the fuse in the under hood fuse box. My add on trailer wiring was casing a short and blowing the fuse. I unpluged the trailer wiring and no more blown fuses! If I am right you owe me a beer!

 

[climber-420]

Update: I stopped by an auto parts store after work. I pulled the cover, and accessed all 3 bulbs. All bulbs were fine. I even replaced the lowest bulb(tail light/ brake) and those looked fine, but replaced anyway. Still doesn't work. I think the wiring has something to do with it. Haven't had time yet to break out the multimeter and dig into the circuitry. I have checked all bulbs, and they are fine. I have checked all related fuses, and those are fine as well. Headlights on......tail lights still don't work. I am beyond confused on this.

Deadbeat........I may have to take you up on that offer. I leave out of town on Monday morning for SLC (Outdoor Retailer Show......return Wednesday) I must have this issue resolved ASAP. Beers and gratitude for anyone that can help me out. Thanks.

 

[deadbeat son]

Deadbeat........I may have to take you up on that offer. I leave out of town on Monday morning for SLC (Outdoor Retailer Show......return Wednesday) I must have this issue resolved ASAP. Beers and gratitude for anyone that can help me out. Thanks.

It looks like the earliest I will be available will be 1:30 or 2:00 Monday afternoon. Just to reiterate a previous suggestion, did you check fuses in both fuse blocks? (Inside cab and also under hood...)

 

[MoabDave]

If you solve the issue, please be sure to come back and let us know what it was. I have odd backup light issues right now, and only backup lights. Everything else works fine....

 

[jgardiner]

Did you test or replace the fuses or just look at them? A visual check does not always work.

 

[155mm]

You'll have to test everything along the way that interacts with it. Sucks, but that's how stuff seems to be now.

On my Chevy Impala, my left and right brake lights wouldn't work, BUT the rear left/right blinkers DID work even though they are the exact SAME filaments that should light up with the brakes on.

Turns out the hazard switch was going bad. Swapped that out and the left and right brake lights started working again.

 

[ToyoTitus]

When you checked the fuses, did you also check the TAIL relay? I've had that relay go bad, causing the exact issue you are describing.