I have a 2007 Classic 2500HD 4x4. The third brake light doesnt work, nor the cargo lights. The regular brake lights work fine. I have changed the bulbs and have found all the fuses in the fusebox are good. Before I start taking interior apart any other ideas?

Second issue is the check engile light. Went to Autozone and the reader said it was not connected to the truck. Tried a diffrent reader (non autozone) and the truck still would not communicate with the second reader either. The plug looked there was some dirt/lint in it, so I cleaned it out and tried again but again no deal. Any Ideas?

Thanks for any help yall can give me.

 

Are you getting any voltage at the CHMSL fuse in the I/P fuse block? As for the OBD connection problem, check the CIG LTR fuse?

 

I will check them this evening. Thanks for giving me a place to start.

 

Both the chmsl and lighter fuse were blown. Brake light works now and I will get a reader on it ASAP. Thanks again