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.