unfortunately, I do not... I drive a Jeep... Traded my 04 F150 in for my Jeep years ago. This is my wife's truck. I'll check all the fuses again in the morning, specifically the ones to the pcm as well as all the others while I'm at it. since there's a 100% chance of rain tomorrow, I doubt either of us will be working anyway.

 

Being that it's intermittent. I doubt fuse or relay would be involved. But always good to check.subs take the pcm in and have it looked at by a dealer. Only the 3 connections and a 4 bolts.

 

they can just test the pcm without having it in the truck?

 

I would call before I went but I would imagine it would be something they could do. If nothing else they might have another model them or they could stick it in to test it

 

No power is a good sign, that means computer is fine its just not getting power to turn it on, you did check with key on correct? the ecm relay is in vehicle it then powers up fuse 32, 33, and 34, check power at those fuses just dont see if they are good but test with a testlight. i believe relay is 203 0r 3 its the top right of the larger relays, my diagram shows it gets it ground around the kick panel, maybe someone loosened to hook something to it.

 

bad ground between motor and frame....I've seen that before...torque it a bit and see what happens...GL

 

Relay 203 was apparently the culprit. The center terminal is actually starting to melt the plastic around it. What can I check to find the reason for this thing shorting out, or is this something that just happens with these relays?

 

Well it runs alot of things, but all are fused, so if no blown fuses must be in spec. the problem is they keep making relays smaller and smaller with smaller pins handling 30amps and your truck is 10 years old, and mostly made outside of this country so it did pretty good really, might take a tiny icepick and make sure the contacts are tight where relay goes into.

 

well, the wife's driving it to work for the first time in a week, so we'll see how it does. Hopefully I won't have to go tow her out.

 

Glad you seem to have it figured out! To me it's weird that a relay would cause an intermitent problem, but stranger things have happened.