My tail lights went out. I have changed the fuse and also the brake relay fuse. They both quit working at the same time. What else could it be??

Did you replace the fuse with one of the same amperage as original? A higher or lower amperage fuse will cause the lights to not operate. Also remove the rear taillight assemblies and the covers over the "computer" assembly, basically a small circuit board behind each taillight, and check for shorts, breaks, or loose wires. These circuit boards are known to go bad.

Yes we used the amp and we have looked at the ciruit boards and they look fine but we are going to take it to a professional. thanks for your suggestions.

not sure if it helps but my 89 C1500 had the same problem turns out it was something to sdo with the turnsignal switch and the relay and sensors. in the steering colum

the wiring harness did it to me try that

check the wiring on the back right where it goes from the frame to the box it might have corroded wires this is very common on these trucks

have you checked to see if you have a good ground, sometimes if you just reconnect the ground wire somewhere else that can help

sounds like your break light switch has gone bad is located on bottom of stering collum,right behind the break peddle.

Run a wire from the negative post on your battery to your frame and then run another wire from your frame to your bed and that might fix it. That's what happened to mine

I HAD THE SAME PROBLEM, CHECK YOUR GROUND, ITS VERY POSSIBLE THAT THE GROUND BECAME RUSTY AND ISNT WORKING PROPERLY.

i have a 93 and i have done changed all that in my case it was the turn signal switch but you best bet is to take it to a shop so they can trace down all the wiring and check it then go from there.

There's a switch under the brake pedal also. Try that. It went bad on my Dad's '94 a couple times.

I have the same truck, and had the same problem in a two week span. Chevy is great, but they have problems with the contact plates. That fixed my problem, try changing those...

connector plates... sorry.

do you have a third brake light if so does it light up if so its your turn signal switch

my 89 one ton has problems with the brake lights sticking on. even when every single fuse is out.all of them. have to disconnect the battery to avoid killing it.last time this happened I didn't notice until battery was dead and taillight assembly had partially melted.nice,huh.replaced light switch,brake pedal switch,all new fuses of proper amperage,and still nothing.hooked up to trailer and trailer lights all work properly. replaced taillight assemblies and worked fine for a year and a half. been another year and a half,time to replace again. stock up!

At the connector (wires plug into tail light housing) the plug sits down onto pins attached to the "circuit board". If one of those pins are bad or have gotten sloppy in their seat, the connection to the board can/will be compromised. My 98 started losing turn signals if the lights were on

but had them wen lights were off. Spliced new wires and plugs, bought new bulbs, lifted tabs under board and flattened out the board strips, and throughout all that they would work sometimes and then they would quit for a while, I'd try the next thing and they would work for a while again . They eventually quit all together and I discovered that particular pin was bad. I pulled pin with needlenose and the one for the backup lights. I put the b/u pin into the t/s pins hole. I don't have b/u lights but have NOT had any probs out of t/s in the 7months since

my wire harness to the back lights at the end they all test possitive, what is the problem

my 1997 chev c1500 350 vortec 2 wd. All my rear lights went out. Had shop fix it 2 times for same problem. So I installed a new brake light system, using no truck part, now all lights work great, no problem with lights at all. Truck brake lights do not work but my new brake light system does work. Flashers and turn signals work too. --- New problem, if cruise control is on and turn lights on, cruise control turns off. Have been told maybe light switch is bad so will be putting in light switch if I can get dash off.

Had same problem. Circuit board WITHIN taillights. $30 at O'Reilly. This was AFTEr spending hours chasing wires, cleaning up trailer hitch wiring, bulbs, downloading schematic, etc.

I have a 95 z71 I have no break light or rear turn sig the running lights wrk all fuse are are good do I need to get the brake an turn sig relay or chase down the wireing??????

I have new circuit boards fuses

77 Chevy Blazer that I replaced the column plate for the turn signal/emgcy flasher, and since then I installed higher amp fuses which made things smoke under the dash, so I changed back to the suggested fuse/s and the brake lights fuse keeps blowing, and running lights don't work at all. Is this the relay, and if so where is that located?

I have a 1989 gmc sierra my trail lights won't come on at all. ..I replaced the on of switch and dimmer switch...still nothing ..help , anyone. .

My passenger break and turn signal are out changed fuse and bulbs still nothing help :(

I guess I'm wondering where should I start

I have a 2000 k2500, brake lights would not work. Stupid as it is, replace the burnt out bulb in the 3rd brake light, as in , on the back of the cab , and presto, problem fixed! Leave it to GM. I guess it's better to have no brake lights than no 3rd brake light.

Ya it ended up being the Tail Light Circuit Board cheap and easy fix :)

It was my granddaddy truck. The manuel is missing and the fuse door is missing so I cant read the fuses to see what is not working. Chevy Z71 Model #C1500. I am trying to found the fuse number that goes to the tail lights on the truck

it should a 20 amp fuse

I have the same problem going on. Driver side running lights and reverse light don't work. Break and turn lights do. I replaced bulbs, circuit board thing, fuses. Nothing seems to work.

its the 7866 relay in the lower right corner of the stupid fuse box- go figure, what a waste of my time - relay all the time.

my 94 k1500 tail lite went out check simpel thing frist it was parken lite fuse , cheep fix $ if ur dash or guage lite is out ur tail lite is also , that GM way to let u know

My brake lights come on but my tail lights arent working. Would a radio system blow some out

1997 Z71 here. My tail lights are not working. I couldn't find any blown fuses, I replaced the bulbs, and then ended up replacing the circuit board bulb holder and they still don't work. It was parked for a while when I had my car and rats got into the engine area and chewed some wires into. I had those repaired. He may have missed one.

pull yr spare an where the frame an bumper connects check the little connecter. if you got any loose wires or termanals in the haness(connecter) its not guna work

My cars 1996 camero rs tail light fog lights dash light don't come on I replaced all the fuses in the hood and inside The dash.. Still no running lights

I am waiting for a genius, someone to tell me why all the lights on my truck work except the rear turn and brake light, only on the driver's side.

That would be a bad ground wire Cowboy29

Hey guys, My drivers side rear lights are having issues as well. The blinker will work, but doesn't flash in sequence with the front blinker on the same side or the opposite sides front and rear. When I turn my driving lights on, I have power back there, but they aren't very bright. When I turn on the right turn signal all lights go off and the same when I hit the brake. I cleaned my ground wire connections up and reattached it. Didn't solve the problem. Any ideas?

Make sure the front turn signal bulbs are only turned 1/4 turn after shoving them into the socket if you go any more than you touch both contacts and it shorts the system out.

1st clean the ground to the rear harness. 2nd check the stop crtsy and turn fuses. 3rd check the bulbs and make sure there is no broken filaments. Front and rear. 4th test light pin the connectors at the tail lights. If no power go to firewall under brake booster. If no power go to the blade connector under the steering column and brake switch.