Brake lights won’t work?

[davidmcclung576]

Hey there so I have a 1994 k1500 and when I turn the headlights on the taillights come on in the back now I think it’s the brake lights that are constantly on along with the running lights because when I took the cover off the middle light and the bottom light are on constant. The top ones don’t come on at all and when I turn the blinker on the middle light turns into a blinker so I realized that the blinker light and the bottom light stay on constant when the headlights are on. However my brake does nothing to change the light sequence. They just stay on. So is it the top bulb that is the brake? I changed the bulbs around thinking that it might have just been that both bulbs went out but that’s not the case they are good. So what’s the top bulb for and why do u suppose my brake lights don’t work? When the headlights are off the blinkers in the back work but I got no brake light again. Also something to note is I changed out the headlight switch thinking it was the culprit but no such luck. Same issue. Is there a tail light/brake light relay somewhere? I’m just baffled. thanks guys! I hope we can figure it out. Also my dimmer was acting funny so I took it apart and cleaned the corrosion/bent the arms out better for connection and now my dash lights work thank god. But yeah still no brake light.

 

[davidmcclung576]

Hey there so I have a 1994 k1500 and when I turn the headlights on the taillights come on in the back now I think it’s the brake lights that are constantly on along with the running lights because when I took the cover off the middle light and the bottom light are on constant. The top ones don’t come on at all and when I turn the blinker on the middle light turns into a blinker so I realized that the blinker light and the bottom light stay on constant when the headlights are on. However my brake does nothing to change the light sequence. They just stay on. So is it the top bulb that is the brake? I changed the bulbs around thinking that it might have just been that both bulbs went out but that’s not the case they are good. So what’s the top bulb for and why do u suppose my brake lights don’t work? When the headlights are off the blinkers in the back work but I got no brake light again. Also something to note is I changed out the headlight switch thinking it was the culprit but no such luck. Same issue. Is there a tail light/brake light relay somewhere? I’m just baffled. thanks guys! I hope we can figure it out. Also my dimmer was acting funny so I took it apart and cleaned the corrosion/bent the arms out better for connection and now my dash lights work thank god. But yeah still no brake light.

 

[jd33173]

1. Check the grounds, especially for the rear tail light harness (this is number 1 for a reason)
2. Un plug the harness and check what you are getting at the harness coming from the front of the truck w a test light.
3. Go through each function and see exactly what is and is not working.
4. Check for wiring weirdness at the back of the truck(trailer lighting, massive tapery, flux capacitor connector, etc) and disconnect it so you can rule stuff out.
5. Brake switch working ok?
6. Flasher ok?
My .02

 

[davidmcclung576]

1. Check the grounds, especially for the rear tail light harness (this is number 1 for a reason)
2. Un plug the harness and check what you are getting at the harness coming from the front of the truck w a test light.
3. Go through each function and see exactly what is and is not working.
4. Check for wiring weirdness at the back of the truck(trailer lighting, massive tapery, flux capacitor connector, etc) and disconnect it so you can rule stuff out.
5. Brake switch working ok?
6. Flasher ok?
My .02

Yeah blinkers work but seems fast. I thought a blinker was out when I got it at first cuz I know that’s a tell tale sight of a blinker out but nope they all work.

 

[davidmcclung576]

Yeah blinkers work but seems fast. I thought a blinker was out when I got it at first cuz I know that’s a tell tale sight of a blinker out but nope they all work. Thank you for responding those are all things I will check tomorrow. I’ll update when I find out.

 

[davidmcclung576]

1. Check the grounds, especially for the rear tail light harness (this is number 1 for a reason)
2. Un plug the harness and check what you are getting at the harness coming from the front of the truck w a test light.
3. Go through each function and see exactly what is and is not working.
4. Check for wiring weirdness at the back of the truck(trailer lighting, massive tapery, flux capacitor connector, etc) and disconnect it so you can rule stuff out.
5. Brake switch working ok?
6. Flasher ok?
My .02

Where is the brake switch?

 

[GoToGuy]

Above your feet, follow the pedal shaft up. The turn signal and brake are the same bulb filament. A brighter light. Running light is not as bright. If you don't have it, in a sticky above is thread to it download for FREE , OE service manuals for your year truck. Has everything you need , the wire diagrams, all basic knowledge how to.

 

[GoToGuy]

Didn't you already post this?

 

[Hipster]

Check the ground forward of left rear bumper bracket, a bolt through the rail with an attached ground, notorious for non-grounding. The tail lights have circuit boards that can go bad as well.

 

[movietvet]

Have you checked the brake light/stop light switch? Has power in/constant, but does not send power to brake light bulbs till the plunger portion is depressed.

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