My 2001 Suburban has no brake lights even though everything seems to be functional. I have replaced all 3 fuses (STOP LP, VEH STOP, CHMSL), replaced the brake switch & bulbs.

Since none of the lights work and the 3rd brake light is on a separate circuit, it would make sense that the problem lies around the switch.

I also want to throw in the fact that there are trailer brakes on my vehicle. Just by chance I hit the manual brake button on the trailer brakes and to my surprise all the lights came on so all the bulbs and fuses work.

Just in case the trailer wiring was causing the problem, I unplugged the trailer wiring from the under dash, completely disabling it, and tried the brake pedal again and nothing happens.

I am now really confused as to why they work with the trailer brake button and not the and not with the pedal.

The next thing I think I am going to try is to replace the brake switch again in case it has gone bad.

Does anyone have any other suggestions?

Does the fuse box underneath the dash have any bearing? That's where the trailer wiring was plugged into.

TIA!

 

Were you able to find out what it was? Mine has the same problem.

 

No one has any insight. I am having the same issue with my 2003 Suburban.