Brake lights not working?

Have you checked the bulbs? They are a double filament bulb. One filament is on when the lights are on and when you press the brakes the other filament lights up. This guide can help us fix it

https://www.2carpros.com/articles/brake-lights-not-working

Check that and if that doesn't work let us know.

I have attached the wiring info for the trailer wiring. In both it states the white is a ground wire. So it should connect to the frame. I can not see from your pic, but is there a bolt, screw or something right near the wiring harness within reach of the white wire? The end of the white wire looks like it was pull out of something if I can see it correctly. I would ground it and see your results.

Also, since you have now that you have what the wires do, I would turn the lights on, the blinkers, have someone hit the brakes and test the voltage coming in to the connector before the spice and after. If there is voltage in t he wires when the tests are being done before the connector, t then the problem is after the connector. If you dont have voltage even getting to the connector, then it is farther up.

Check out the diagrams (Below). Please let us know what happens.

Okay, so that wire has been added or it seems like it has been. Have you always had this truck. For now definitely tape it off so it doesn't' touch anything. Now what about the other thing I suggested checking? See the above and lets check the other wires..... And tell me what you get.

Looking forward to hearing back from you.....

Hello -

Thanks for the info. It is important to chart it so you know that before the connector when you do this function, this color wire does this according to the info above. And then the same thing after the connector. I can not tell by the pic (thanks for providing that by the way) if you have a red 30 amp wire or a blue 30 amp wire feed. This tells us if you have the UY1 or UY7 towing package.

That is interesting about the white. It looks like according to the pic that the blue part it comes out of was a clamp on elec clip for wire splicing.

Might sound crazy, but both the towing packages, the yellow wire and the dark green wire control the left and right stop lamps. When you look at the wiring harness, does it look like that white wire pulled out of where those wires go in? From the pic again, to me it looks like it was pulled out of something.

My initial guess is if you took a wire and went from that white to the yellow and the dark green and hit the brakes, they would work. I would still like to know what happen there though.

You are welcome for the help.

Hello -

I looked back on what we have talked about and I don't see where it was said if this is a 1500, or 2500 PU. Please let me know and the exact engine and the 8th letter in the VIN.

Also, the pic you attached, thanks, but the wires with the red circle around it. That is hard to see especially with the splice.

Going into the plug the first is DK Green, then Lt Green, then yellow, then what - this is all the confusion area for me to see.

thanks

Hello - Rossickle - may I call you that?

Okay - lets do a recap please to ensure you and I are on the same. I don't know about you but it helps me focus since there are numerous posts between you and I, there is time lags inbetween and, I am dealing with other vehicles.

1997 Chevy Silverado, K1500, 4WD automatic, 5.7L VIN R, 220,000 miles

Based off of the above post on which towing package you have - I would say it is the UY7, heavy duty. Would you?

UY1 - wire colors -
- Dark blue - 30amp auxiliary circuit
- Brown - Tail and license lamps
- Lt Green - backup lamps - (missing from the info provided by the dealer????)
- Dk Green - Right turn signal and stop lamp
- Yellow - Left turn signal and stop lamp
- White - ground

UY7 - wire colors -
- Red 30amp battery feed
- Dark blue - auxiliary circuit
- Brown - Tail and license lamps
- Lt Green - backup lamps
- Dk Green - Right turn signal and stop lamp
- Yellow - Left turn signal and stop lamp
- White - ground

What you currently have

No brake lights on rear other than on topper.
DK Green and Yellow - Blinkers - okay
Lt Green - Reverse - okay
Brown - Tail - okay

I have attached a pic for you that I drew that shows your first pic - this is the wiring harness - correct -the color of the wires and what they go too? Please let me know if this is correct. The red X on the wires mean that from what I can see, those wires are not there. Also, the from the front of the truck, I left the white wire just sitting out there, is this correct? It comes from the front of the truck with the rest and is just hanging?

The second pic you sent where all you have is the harness from the front of the truck, I sent back a circled area that looked confusing.

1. The white wire that I can see no insulation on that is coming out of a blue clip:
a. Is this a spliced in wire?
b. If so - what color wire is it spliced into?
c. Is it hot at any time?
d. Did you splice it in?
2. The white wire that is coming down from the front of the vehicle, I can not tell from the pics - what is it doing or where does the go or is it just hanging?
3. In your first pic where you show the complete harness, thee is a red wire that look like it is coming out of the middle part of the harness and plugged into the blue splice. Is this correct or what is going on here?

A couple of checks also

When you push on the brakes - the Dark Green and Yellow wire going into the harness - do they then have 12v but when no brake nothing?

With the lights on - do the Dark Green and yellow have any volts?

When you have the lights on and hit the brakes - then to the dark green and yellow have 12v

Also on the pic that has the red circle on it, it looks like the wires from left to right are dk green, lt green, yellow and then the next hole is empty on the connector. . ..is that correct?

Last - they system was working. . .you have 200+ miles. Have you recently ran over something, when did you notice they weren't working?

If you can answer these questions that would be great. Let me know what ever corrections I need to make.

Bob

Hey one other thing.........when you turn your emergency flashers on - do the other lights act the right way ie the fronts flash etc?? If not change the hazard flasher and then check it.

Excellent addition to this thread! Please feel free to help out whenever you are on the site :)

Do the rear turn signals work? Does the third brqke light work or are they all out?