PCM power relay

My 1998 Ford Explorer sport was working fine and a few hours later when I went to go home it wouldn't start. I changed the altanator thinking that was the problem but i still wouldn't start. The battery light and check gage light came on. Checked a spark plug it wasn't firing. When I went and checked the fuses the 30 a fuses was bad for the PCM power relay replaced it and it did the same thing. Was hoping someone had an answer for me. Thank you.

Are you saying the vehicle will still has no spark, or the fuse blew again? If it is still a no spark, look to the crankshaft sensor. If the fuse blew, it is a matter of chasing wires until you find a short.

Thank you for th reply. The fuse blew again. I didn't check the spark plug again cause it was the same problem. The PCM controls sveral things from my understanding.

Yep, the PCM relay supplies power to several circuits. It will be an experiencing tracking down which one. You'll really need a good wiring diagram for the truck.

If you would like a copy of the factory wiring diagram, send me a private message with your e-mail address.

-Rod

Thank you again will do.