I have a 2005 GMC Sierra 2500HD and my OBD2 port wasn't working. So I went to check the fuse and it was blown. I pulled out the radio fuse (both 15 amp) to test it, and it instantly blew. I am not sure where to go from here.
EDIT: My truck was a work truck for the state I live in, not sure if that makes a difference but thought I'd include that.
Hello all, I want to thank all who responded to my post! I did fix the problem; it was the cigarette lighter shorting out the system. Now I don't know why it was doing so, but I just unplugged it completely and now I have a working OBD2 port!
check some wiring diagrams
the OBD port often shares the circuit with the cigar lighter
Make sure there's no rust or schmutz in either socket. Then inspect the wires
something like this will do it
Clearly a dead short somewhere. Find the hot wire to ground and you've found the problem.
