rr brake & turn signal dont work

[GUEST]

I’m having the same problem and also my hazard fuse keeps blowing
No hazards /signals dash /front /or back
No break lights wondering should I change flasher relay please help thanks alot

[carriedi]

Blowing fuses: I would look for a short. probably an intermittent short. Check the wiring. verify you are using the right light bulbs,

fuses work by burning out when too much current runs through them. That's load on the circuit.

You may need to use an ammeter that you can graph and drive the vehicle around and see when the amps get high

[GUEST]

You need to do some electrical testing. Your brake lights and tail lights are powered by the body control module. there is a park light relay and fuses for the park lights under the drivers seat. Check the Rt rear park lamp fuse. There are 4 fuses for the BCM in the under hood fuse box.

the right rear turn and brake comes from the BCM. they go to the drivers fuse box and then to the brake lights in the back. the right rear turn should be on the dark green wire from the bcm to the drivers under seat module. It comes out as dark green from the module but it turns to a yellow wire at the light.

With the right turn signal turned on, does the front turn signal flash? If the front is flashing then you need to check the wiring at the BCM and see if it is sending the signal to the light in the rear. If the Bcm is sending out the signal to flash the light then follow the wiring until you lose the signal to find the open in the circuit. Or, check to make sure you have a good ground at the light socket.

Thank you! Still havent learned the "try the simplest fix first" apparently. But, in fairness, all but one parking light was working. Until I read your post I had no clue any vehicle had a seperate fuse per parking light! Problem now solved!

[Guest]

On my 2017 express 3500. It bcm-6, which is fuse location 72.

[carriedi]

this should be what the underhood fuse box should be like

[Freddie]

None of my rear lights work ( brake, tail , signals, and reverse lights ) I checked all fuses and there fine . Where do I go from here?

[carriedi]

If none of the rear lights work (brake, turn and reverse) and all the fuses are good, I would look at the wire harness connection. there should be a connector the goes to all the rear lights in the wire harness. See if it has been cut or unplugged.

[Travis]

So some guys hooked a trailer up to my Chevy 2500 express 2016 model. Since then my driver tail light doesn’t work nor does my trailer running lights. All fuse are good, even took to another shop today and they said they couldn’t figure it out. Any suggestions would be great.

[carriedi]

the tail light fuses are under the drivers seat. LT REAR PARK LAMP FUSE. RT REAR PRK LAMP FUSE. Thay both get power to the fuses from the park lamps relay. If you have power on both fuses but one tail light doesn't come on you have a bad connection the the light that is out or you have a bad/wrong bulb in the tail light. Is the license plate light working? Brown wire is for tail lights. Both sides and license.

I would completely remove the trailer wiring first and then see how everything works. Probably could be a bad wiring job.

[905hvac]

Hey I got a 2019 gmc savana 2500. Both my signals flash rapidly but all my signals headlights etc are fine, could This model have a relay that’s wired to the signals that’s bad or is it all controlled by the bcm? All lights are replaced & are oem and I bought the car like this. Hoping it’s not to do with a bad ground.

[carriedi]

there's no flasher for the turn signal. They use the BCM to pulse the turn signal. As long as everything works, I would just let it flash fast.

The bulbs for your vehicle should be 3157. It is possible that someone replaced them with 3057. I don't know if that would cause the fast flash though. They are slightly different in lighting and power usage but I don't know if that would affect the flash time.

https://rxmechanic.com/3057-vs-3157-bulb/

[Guest]

So my passenger rear blinker and driver side headlight aren't working. Front right blinker has the fast blink.