[Darren McElroy]

Hi everyone. My 1996 K1500 pickup has no brake lights. I have turn signals, tail lights, backup lights and hazard lights, but no brake lights.

I changed the bulbs and checked the fuses under the hood and next to the drivers door. I also changed the relay under the hood in the fuse box. The cruise control responds to the brakes being pushed in so I felt that the switch at the pedal was likely good. Could the pedal switch work for the cruise control and yet not for the brake lights. any help is appreciated. Thanks

 

[j cat]

If this were a 60's gm truck the brake light switch is just that brake lights. on a 96 the brake pedal switch controls many components and IN my case I got a ABS code because the brake pedal switch one of I think 7 switches was not working . so my guess with what you checked the brake pedal switch that controls the brake lamps may need cleaning or to replace the complete switch . I did take my switch apart have GM manual so I knew what wires went to the components. then used OHM meter to see if the switches worked .

used a 1960's ignition point file problem solved.
could be a wiring problem also if switch tests good.

 

[Cowboytrukr]

The brake switch is a three contact switch. One for the cruise, one the brake light, one the torque converter lock up. It could easily have one contact defective.

Tough to get in ther to pull it, but it’s worth checking the switch.

 

[Darren McElroy]

The brake switch is a three contact switch. One for the cruise, one the brake light, one the torque converter lock up. It could easily have one contact defective.

Tough to get in ther to pull it, but it’s worth checking the switch.

Thank you. I will go ahead and change the switch. That was just the info I was looking for. I had wondered if that switch was multi function.

 

[Darren McElroy]

Well, I have now changed the Switch. There is no excuse whatsoever for the difficulty involved in changing out that switch. Very poor engineering. Anyway, the switch was not the answer. Still no brake lights. I have now changed the switch, the relay, and the bulbs. I have checked the fuses with a meter and they are good. Is there a third fuse somewhere that i am missing ? The terminal sockets at the relay do show a change when i access the brake so at least the relay is receiving a signal from the brake switch. Any ideas ? Thanks

 

[RayVoy]

Use your meter on the DC volts scale and trace voltage

 

[j cat]

check for a interface tow connector under the rear of the truck bed . could be corroded connections ..

 

[Darren McElroy]

Use your meter on the DC volts scale and trace voltage

I have no voltage at either the fuse under the hood or at the fuse at the drivers side door panel. I do have voltage at my third brake light on the back of the cab and it does indeed work but I have nothing at the brake light bulbs. I will look for the interface connector and see what i can find. Thanks

 

[Darren McElroy]

I am using a concrete block to hold in the brake pedal. Shouldn't I have 12 volts on one side of at least one of the fuses ? I seem to have power at the relay, but no further. I changed the relay with no results.

 

[RayVoy]

I've not seen a brake light circuit with a relay

 

[silverado002]

Darren, Like Ray says above there shouldn't be a relay in a brake light circuit. I think the brake light circuit goes thru the brake switch and the turn signal switch for a 1996. Do your turn signals work ok?
Also, like Jcat says, there should be a connector under the rear of the truck where you can check for voltage for the brake lights. The colors should be yellow for the left side and green for the right side I believe.

 

[Darren McElroy]

Darren, Like Ray says above there shouldn't be a relay in a brake light circuit. I think the brake light circuit goes thru the brake switch and the turn signal switch for a 1996. Do your turn signals work ok?
Also, like Jcat says, there should be a connector under the rear of the truck where you can check for voltage for the brake lights. The colors should be yellow for the left side and green for the right side I believe.

at the sockets for my fuses on either side of my fuse. It is if no power is making it to either of my brake circuit fuses. I have replaced this relay with another one but still no brake lights. Whether or not this relay is supposed to be in the circuit or not is beyond me but it certainly acknowledges my brake switch activation. My truck might be unique, lol. When I replaced a door hinge pin once the local dealership went nuts trying to find the right part number. It turns out that the factory used a pin and hinge system for a completely different model of Suburban and it would not match my Z71 K1500 pickup. I hope to get under the truck today and check the connections back to the fuses and spray some contact cleaner on them. But again, I have no voltage at the fuses at all.

 

[Darren McElroy]

I have no idea where the first part of my message went to Silverado002. Sorry. The relay is located under the hood in the fuse/relay center on the drivers side. It reads " Brake Lamp Relay ". When I activate the brake switch on the pedal the socket terminals for the relay do change states and voltage reading of 12 volts that do change. I get nothing at my fuses at any time.

 

[xPosTech]

That's probably for the trailer brakes. The truck and trailer are separate circuits and separately fused. The relay would isolate the two circuits.

I didn't look at the schematics so I'm only guessing here.

Ted

 

[Darren McElroy]

I finally have my break lights working again !!!!! It turned out to be the brake lamp relay after all. I had purchased a new one at Oreilly Auto parts last week but it did not fix the problem. I followed my gut today and bought another again from the same store. This relay solved the problem. I couldn't get over the fact that I had 12 volts to the relay but nothing at the fuses when the brake switch was made. Advance Auto parts and Autozone were not helpful because neither of them carried the relay or even seem to know what I was talking about. At Oreilly's, it is possible that the first relay that I bought was a dud. Who knows. My truck has a towing package but for some reason, there is only the flat trailer light plug. There is not the round socket plug that I have on my other truck and suvs. My flat plug is a 5 pin that will release the brakes on my boat trailer while backing up. I have not used this truck to pull that boat in several years. Anyway, thanks to all of you who responded. I am very grateful.

 

[silverado002]

Good for you. That's a relief. Never heard of a relay in the brake circuit for the truck brakes so there must be some kind of option based on what type of trailer package you have.

 

[j cat]

this is why I say new does not mean good ... when people guess on whats broke and throw in new parts many times it creates more confusion . need volt meter to test these type failures .

 

[bob Lewis]

In the taillight assembly there is a taillight circuit board. If you have checked all the other items, than you would just need to remove the taillight and replace the boards. This board fits all 88 thru 98 ck models, tahoe and includes the 99 burb using the . This is a common problem for no brake lite. You can find at most auto parts stores or ebay.