Hey, my first time on the site! and with a question of coarse. My son's 98 cheyenne 4.3L 4x4 will not turn-on my scan guage so that I can read the trouble code for the check engine light. I believe the gauge is okay as is comes on as soon as I plug it into another vehicle. Any suggestions as to what to look at first? I have used the gauge in the past without problems on this truck. Thanks in advance.

 

Yes the obd2 port is powered by a fuse. I think it is the ecm fuse not sure just check all the fuses and that should fix your problem

 

I checked the fuses, all are good. What next? Thanks

 

Thats the only thing i can think of. You could take a test light or a fluke meter and probe the wires to see if it has power to it.

 

thanks, i will try that