GMC Sierra No brake lights

Ask our auto mechanics for help to all your GMC truck questions.
Post Reply New Topic
dirtman
Posts: 7
Joined: Sat Apr 27, 2013 7:53 pm

GMC Sierra No brake lights

Unread post by dirtman » Sun Feb 08, 2015 10:36 am

2006 gmc 3500 sierra have no brake lights or cruise control. new brake switch && have checked fuses many times. Also the tow button on shift leaver does not work. Have checked all fuses with test light & ohm meter. Does this truck have a cruise mod under the dash that controls all of these things.
Truck has duramax & Allison trany.

 

User avatar
carriedi
Posts: 2267
Joined: Wed Apr 10, 2013 12:42 pm
Location: Oregon

Re: GMC Sierra No brake lights

Unread post by carriedi » Sun Feb 08, 2015 11:48 am

for models with the 8.1L engine (other engines have slightly different wiring) let me know if you have a different engine.

there are 5 fuses that go to sections of the cruise control.
VEH STOP (15A), BRAKE (10A), CRUISE (10A) in the dash fuse panel (lower left side of dash)
ETC/ECM (15A), STOP LPS (20A) in the underhood fuse panel (near battery)

if you have checked all five fuses and they are not burned out then have you checked to see if they power up when the key is on? Stop lmps should have power all the time. the VEH STOP should have power when you press the brake pedal. the others should have power with the key on run.

If all the fuses check out good and the power also checks out okay you should check to see if your turn signal flasher is working correctly. It does a lot more than just turn signals now days

dirtman
Posts: 7
Joined: Sat Apr 27, 2013 7:53 pm

Re: GMC Sierra No brake lights

Unread post by dirtman » Sun Feb 08, 2015 6:09 pm

Just to clarify the truck is a 2006 GMC 3500 with a duramax 6.6 and Alison 6sp auto.
have checked fuses several times. There is no power to the orange wire at the brake switch from the
stop lamp fuse under hood. This truck has a tow button on gear leaver that is not working also.
I think there is a cruise mod. under the dash that may control all of these things.
Also is there a web site I con go to for a wiring diagram of just this truck.

User avatar
carriedi
Posts: 2267
Joined: Wed Apr 10, 2013 12:42 pm
Location: Oregon

Re: GMC Sierra No brake lights

Unread post by carriedi » Sun Feb 08, 2015 9:03 pm

if you do not have battery power on the orange wire then you need to check to see if you have power at the STOP LP fuse. if you don't have power on both sides of the fuse you may have a bad fuse panel. if you have power on one side but not the other, you know you have a bad fuse, but if both sides don't have power then try using a jumper (fused jumper) and see it you can get everything working with adding power to that circuit.
Attachments
gmc top half.jpg
gmc top half.jpg (153.25 KiB) Viewed 3426 times
gmc bottom half.jpg
gmc bottom half.jpg (79.19 KiB) Viewed 3426 times

MyBr260
Posts: 1
Joined: Fri Apr 17, 2015 6:17 am

Re: GMC Sierra No brake lights

Unread post by MyBr260 » Fri Apr 17, 2015 6:30 am

I have a 2003 GMC Sierra and I'm not getting the right brake light to my trailer. The problem is with the truck the trailer wires check out fine. Any ideas?

User avatar
carriedi
Posts: 2267
Joined: Wed Apr 10, 2013 12:42 pm
Location: Oregon

Re: GMC Sierra No brake lights

Unread post by carriedi » Sat Apr 18, 2015 10:56 pm

make sure the fuses are good in the left instrument fuse panel. L TURN, R TURN, VEH STOP ans VEH CHMSL

If your truck has separate turn signal and brake light bulbs in the back of the truck, then you have a four light system. Two brake lights and two turn signal lights. Most trailers only use a two light system. the brake and turn are combined into one circuit. So you would need an adapter to make your truck work on a normal trailer. These adapters go out all the time. Check to see where the adapter is and check the wires going in and see if they are running the correct circuit signals. If they are then the adapter is probably going to need to be replaced.

Post Reply New Topic