tail lights dont work


Asked by Aug 14, 2013 at 09:16 PM about the 1991 GMC Sierra 1500 K1500 4WD Standard Cab Stepside SB

Question type: Maintenance & Repair

The brake lights, turn signals, reverse lights all work but the tail lights ( when you head
lights are on ) do not work. i have changed the bulbs, fuses, checked the tail light circut
board, checked the headlight switch. when i checked the wires at the tail light only the
wire that worked the turn signals had juice the other 3 did not. electrical is not my strong
point so any help would be appreciated

28 Answers

grab your circuit tester to find out that they aren't getting sufficient chassis ground....coarse wirebrush the 1/0 battery cable as it attaches to the frame so the frame itself is grounded properly...test the ground at the tail lights....you'll be good to go with a brand new battery -----5 years is all you want else screw up your alternator~

11 of 11 people found this helpful.
Best Answer Mark helpful

you will need a test light, like the judge says- poke it into the socket where the inop bulbs are- identify those wires and follow them back testing as you go- a lot of times, the sockets are corroded and just need to be scraped out and new bulbs replaced

4 of 4 people found this helpful.

still a no go any other ideas?

3 of 3 people found this helpful.

of course the fuse...which if blown should tally up the reason for failure...might have been something as simple as a hershey's kisses wrapper in the wrong spot "kissin" the fusebox~?

1 of 1 people found this helpful.

I just checked all my fuses, all were good. I checked the bulbs, all were good. I checked to see if I had power at the plug into the lamp, no power for the running lights. Hopped under the rear bumper and found where someone had done a crappy repair on the brown wire coming in on the main harness and it split off to two brown wires to each light and fixed the repair and lights work now.

6 of 6 people found this helpful.

Also each bulb has its own ground at the rear, and mine was fine.

3 of 3 people found this helpful.

im having the same exact issue with my 87 gmc sierra. did you figure out what your problem was?

11 of 11 people found this helpful.

I'm having a similar issue with my '96. My headlights, front running lights rear turn signals and brake lights all work. My rear running lights are the only lights not working. I've checked the fuses, replaced the circuit boards, replaced the bulbs, resurfaced the ground and tested the sockets. The rear running light plug is the only plug not getting power.

30 of 30 people found this helpful.

I had this same issue and come to find out under the hood there is a fuse for each side for the running lights that solved it for me.

20 of 20 people found this helpful.

On my 1994 GMC my instrument panel lights quit working and the tail lights also. I replaced the wheel dimmer switch for the instrument panel and then my tail lights also worked.

15 of 15 people found this helpful.

I have a 96 chevy truck hazard lights work but the turn signals stoped working any ideals fuses r good

12 of 12 people found this helpful.

Fuse under the hood fixed it!!! Thanks jr

6 of 6 people found this helpful.

I found the wires going to the tail light hang 1/2 inch below the bumper. Something hit the wires hard and cut them in two. There is a connector at the center of the back bumper.

4 of 4 people found this helpful.

2001 dually contractor bed front lights work properly rear light , stop lights hazard light signal lights , and parking lights doesn't work, they gone, relay and fuses, relay and bulbs are good, how to fix them?

4 of 4 people found this helpful.

I had the same exact problem trust me i bought all new boards lights i even followed the line what you wanna do is on the clip that has all of you wires look at the ground its the black wire go back about six inches on both sides of truck then cut and use a loose wire laying around stick it to the frame and wire you two ends to it ive fixed six different trucks with same problem and it has worked to all six so if you bought new lights and board take them back thats not the problem at gm they just throw it together trying to get done at work

5 of 5 people found this helpful.

Ive put in hours and hours of working on my own two now i dont have to worry some dodges does the same thing im not sure about ford


william257cash were is that clip located at

1 of 1 people found this helpful.

96 GMC taillights And tag light won't work. But flasher work. Check the fuses inside all good. Replaced bulbs.

4 of 4 people found this helpful.

Checked fuses inside and under hood all good. Come to find out the problem it was a white and black wire bolted to the frame above the trailer hitch had broken aloose . I ground them and everything started back working. Hope that fix ur problem.


Please help I have a 2005 GMC Sierra 1500 Crew Cab Vin Letter T my right side rear tail light has stopped working the stop light, the turn signal, have all stopped working and when you use the turn signal selector switch on the column when turning right it just flashes very fast indicating it isn't working, the brake light however to my knowledge is still working when you press the brake it lights up but the running light same socket, same bulb does not function I was told that the socket was burned out on one side and needed to be replaced so I went looking for a socket to fix it first not one junk yard had my model truck, and then the auto parts shops started giving me sockets to try, and none of them fit the socket design in other words they will not screw into the socket in the tail light assembly, so one store found the socket I needed none of the standard sockets will work apparently my truck was a special make something about being a transition year IDK, anyway the socket that this one guy says I need is over $60 for a socket all the other sockets I tried before were between $12 and $19, But I am not sure it is the socket this guy has been very wrong on other vehicles he has worked on for our family, in fact he ruined my nieces car they never did get it running again after he worked on it, it was running before hand, anyhoo do any of you have any clue what this might be I have checked every fuse, and replaced all the CB's in the fuse blocks and nothing

3 of 3 people found this helpful.

Found it was the interior headlight switch assembly. Seems with age it gets loose or, I suppose the contacts inside could be dirty. But if I move it, or wiggle it a bit, the taillights come on. Keep in mind, I can turn the knob and the headlights would come on, but not the taillights. For now I will deal with it, but I will look into either opening it up and cleaning it or replacing it altogether.


I just bought a 2012 Yukon denali and im having problems wiyh the taillights not working, licence plate light also don't work. I checked fuses and they seem good? whats next? any ideas?

1 of 1 people found this helpful.

brake light work also

It's usually the socket for the light itself the 3157 bulbs run hot. My resolution was switching to LED tail lights and replacing the connectors.


Check the connection at your trailer light harness

1 of 1 people found this helpful.

Make sure if you have a trailer light harness, to check the connection there as well. I unplugged mine and and went back to factory and everything is fixed now.

wear is the fuse u said that u replace under the hood to get the tail lights working having a hard time finding it

1998 gmc seirra brake lights turn signals and reverse light all work. Marker lights do not work. Brake light only with with head ligh switch off. I've cleaned and replaced all grounds changed the whole rear harness replaced bulbs boards does anyone have any ideas? Also when the head light switch is on the turn signals blink faster.

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