I have an early production 97 (06/96). It seems to only happen when it grts overly hot (as opposed to overheated), but it will eat PCM main power fuses like a fat kid with cake. Last time I had a similar issue, it ended up being the IAT sensor. I've already checked the O2 wiring and those are all good. Went to see if I could figure anything out with it yesterday and she fired up no problem without doing anything. I'm at a loss, anyone got any ideas?

 

Quit posting identical threads, - same new thread yesterday, - https://www.f150forum.com/f6/pcm-power-issues-455121/

Flip the fuse block and look for corrosion under it. If fine/clean, check for short while moving harness around. Also check grounds. Direct PCM ground is on the firewall by the battery.

 

By bad, was trying to find the other post but it was lost in the sauce for me.... 😒

Thanks, I'll check the fuse block and PCM ground....

 

Fuse block is pristine clean on the underside. PCM ground is clean and secure. I pulled the harness off the PCM and it still eats main power fuses. Anyone want a low-mile 4.2L 2WD?

 

Check your PCM relay when the fuse blows. If the relay is hot, replace it.

 

😪 Swapped the PCM relay with a known good one. Problem didn't go away. I hate chasing wires....