I just bought a 03 Grand Cherokee for my son and discovered the brake lights aren't working. The turn signal and reverse lamps work but none of the others do. I took it to Auto Zone thinking that it might be the brake switch or fuses.
The guy at the store was great to help me in the parking lot replacing the brake switch and fuses, only to discover something is blowing the fuse and it's not the brake switch.
I'm trying to avoid getting jobbed by a mechanic so I was hoping it might be a more simple fix.

Any ideas?
Thanks

 

If the vehicle is equipped with a tow package check the wiring harness at the hitch. Part of the wiring harness is exposed under the vehicle and if those wires have been nicked or broken the one tied to the brake lights could be shorted out causing the blown fuses. Also check the plug for the trailer lights, it could be corroded and shorting out as well.

 

No wiring harness.

 

My brother-in-law did install a new radio a few days after we brought it home, could this possibly have something to do with it?

 

nm

 

issue was in the tail light assembly. Tech got in, cleaned the area up and no more blown fuses.

 

I have an 01 wj and I have brake light issues all so. Found out that the "tabs" that hold the bulb in are cheep plastic one side made of a conductor and they bend out with to much use (214000 miles) and it doesn't work all the time if I hit a bump so there's a warning for you

 

Nice to know