How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Jared D Your Own Question
Jared D
Jared D, ASE Certified Technician
Category: Chevy
Satisfied Customers: 1349
Experience:  Shop Supervisor at County Fleet
62275574
Type Your Chevy Question Here...
Jared D is online now
A new question is answered every 9 seconds

2006 Trailblazer brake lights 't work but top brake light

Customer Question

2006 Trailblazer brake lights don't work but top brake light does work. Fuses are good. I changed the turn signal control switch and one of the rear circuit boards, still nothing.
JA: Have you checked the fuse? Have you checked for bad bulbs?
Customer: Yes.
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: 2006 Trailblazer brake lights don't work but top brake light does work. Fuses are good. I changed the turn signal control switch and one of the rear circuit boards, still nothing.
JA: Anything else you think the mechanic should know?
Customer: No.
Submitted: 4 months ago.
Category: Chevy
Expert:  Jared D replied 4 months ago.

Hi,

The brake lights have a separate fuse from the high mount brake light.

Have you checked the fuses in the rear fuse block under the back seat?

Customer: replied 4 months ago.
Expert:  Jared D replied 4 months ago.

Do you have power to the 15 amp fuse #34?

Customer: replied 4 months ago.
Not sure, I didn't check power to it, what if it' has no power?
Expert:  Jared D replied 4 months ago.

It has no power then there is a short in the fuse block. You will need to test for power at that fuse with the brake pressed. If the high mount light is coming on then you know the wire from the brake light switch to the fuse block is good. The best place to start looking is at that fuse since it is essentially the first part of the circuit that you know isn't working.

If you do have power at that fuse then you have a break somewhere between the fuse block and the rear light boards. There should be two light blue wires, one for each side tail light board, coming from the fuse block. You should also see voltage on those wires when the brake is pressed.

Customer: replied 4 months ago.
I have power on the fuse.
Expert:  Jared D replied 4 months ago.

Ok. So at this point you'll want to pull the tail light board and check for 12 volts (again, with the brake pressed) at the light blue wire as it goes into the tail light board. You'll need to check both sides.

Expert:  Jared D replied 4 months ago.

I just wanted to check whether you need more help with this. If not, please don't forget to rate.

Customer: replied 4 months ago.
On the fuse block under the rear seat, with the key on and engine off, there is 11 volts on the large red wire and 8.5 volts at fuse 34. The fuse is good. How do you remove the fuse board to get to the blue wires?

Related Chevy Questions