Hi all,
I have a 99 blazer that hesitates once in a while intermittently. The fuel pump and filter have recently been replaced, and I have ran injector cleanor through the gas several times. Every time it hesitates the service engine soon light comes on. My first guess was some sort of sensor though i am not sure which one. I tried taking it to autozone where they will hook up the odb II for free to try and see what the service engine soon light is referring too. When they plug in the odb, the fuse for the cigarette lighter blows every time. its a 10 amp fuse and we tried replacing it with a 15 amp and it did the same thing. there was nothing plugged in to the cigarette lighter at the time. I cannot figure out why this fuse is blowing. I have taken the dash apart and looked at the wiring to the cigarette lighters and it all looks fine. Does anyone have any suggestions?

 

That fuse does not only control the cigarette lighter. It also is the circuit that supplies power to the OBD connector for the scanner.

You will need to check the harness to the OBD connector for shorts. This is especially common on vehicles with after market remote starts and alarms that have been improperly installed. Those connections should be checked first if you have one of those installed on your truck.

I believe that it is pin 16 (bottom right corner on the side with the notch in it) that is the +12v line that would be shorting out somewhere along the line.