Chevy Brake Light Problems

hsousa1997

Member
Location
Hudson, MA
Hello all. First I hope everyone is healthy and safe during this current pandemic. Meanwhile I’m having an issue with the brake lights on my 2006 Chevy 3500 Duramax dump truck. With all the lights on, when I step on the brakes, the brake lights do not “get brighter”. With the truck lights off, when I step on the brakes, the brake lights work fine, but the parking lights come on. To me this seems like a head scratcher. Any advice on what it might be would be greatly appreciated.
 

Fourteen Contracting Inc.

PlowSite.com Addict
Location
Vaughan, Ontario
I had an issue similar on a Ford F250... there was a ground wire that came out from the trailer wire assembly (going to the back of the truck) about midway between the cab and the back of the truck. It was grounded to a bolt on the frame. It had corroded and broke off giving me the same kind of issues.
 
OP
hsousa1997

hsousa1997

Member
Location
Hudson, MA
I just haven’t had time to look into it recently, and I figured I would post again to see if anyone else had advice. That’s all. But besides that I’ve managed to narrow down the problem. I unplugged the passenger side taillight and everything works as it should. So I’m assuming something is wrong with the light itself or the wiring going to the light. I’m going to order new lights and try that first, as I’ve wanted to change the lights anyway
 

Philbilly2

PlowSite Fanatic
Location
Sandwich IL
I just haven’t had time to look into it recently, and I figured I would post again to see if anyone else had advice. That’s all. But besides that I’ve managed to narrow down the problem. I unplugged the passenger side taillight and everything works as it should. So I’m assuming something is wrong with the light itself or the wiring going to the light. I’m going to order new lights and try that first, as I’ve wanted to change the lights anyway

Left side turn signal trailer is a separate wire from the bcm all the way back to the 4 port connection box inside the rear frame rail. Separate fuse as well.

If I was you, I would try your right signal on the left side and see if your results stay the same or move to the other side. Swap both lights to the opposite sides. see if the issue switches side before throwing parts at an issue.

20:1 odds that your problem does not switch sides and stays on the left side indicating that you have a ground issue on the left side wiring.
 
OP
hsousa1997

hsousa1997

Member
Location
Hudson, MA
I’m probably misunderstanding here, but I just want to clarify before I go further. It’s when I unplug the right taillight is when everything works fine. So wouldn’t that indicate the issue is on the right side, or if I swap the plugs/lights should it jump to the left?
 

cwren2472

PlowSite Fanatic
Location
north east
I’m probably misunderstanding here, but I just want to clarify before I go further. It’s when I unplug the right taillight is when everything works fine. So wouldn’t that indicate the issue is on the right side, or if I swap the plugs/lights should it jump to the left?

Swapping the light with the other side as Phil is instructing will tell you if the issue is with the light itself or if it's a wiring issue that only arises when the circuit is complete.

For instance, it could be that you have a BCM issue but unplugging the light causes it to shut off power to that light (as if you had a lamp out condition) making it appear that the light is the issue when in fact it isn't.
 
OP
hsousa1997

hsousa1997

Member
Location
Hudson, MA
With mine, and more than likely most others, I can’t unplug the lights from the circuit board and swap the plugs as they won’t fit, unless there’s something I’m missing. Would unscrewing the light sockets and swapping those help or no?
 

Top Forums

Similar threads

Similar threads

Top