my 2004 F150 ,4.6 blew the pcm #34 fuse the other day .any ideas on what this fuse is for so I know were to begin looking for the cause. only home 1 1/2 days a week, so not a lot of time to work on it .

 

The Fuse F32 has on it

1. EVAP canister purge valve
2. AC clutch relay in the Aux relay box
3. EVAP canister vent solenoid
4. EGR module
5. PVC vlave
6. Cam position sensor
7 HO2 sensor 11
8. HO2 sensor 12
9. MAFS / IAT sensor

in the 99-03 series usually a blown PCM fuse is a sign of a HO2S harness up against the exhaust pipe, and melted through.

Have you done any work around the HO2S or has xhst work done as of late ?

A search in this forum for PCM Fuse would 73 threads.

 

my pcm fuse kept blowing, turns out an ignition wire was making contact with bare metal when i would hit a big bump... 10 fuses and a couple weeks of head aches later, i found the wire.

 

Got any details for murray1, on where the wire is at ?

There are a few of them in the truck...

 

Just heading out for the week. No work has been done on the truck at all. yesterday was way to cold and stormy to think about looking at it . I've had people say it's a faulty pcm , but it will restart for a few seconds ten blow the fuse again, others say it's my fuel pump drawing to much amperage. I tend to think it would be fuel pump related or bare wires somewere. Will be back home on the weekend but might just have it towed to a garage and hope I don't get sc@#*ed to much.
I really hate taking my truck to the garage when I am capable of fixing things myself. Chances are if I was driving it when it quit and had time to investigate the problem I might be able to figure it out. thanks for any assistance.

 

It was a wire I ran to my fuel pump controller, so that doesnt help him. replace the fuse, it may never happen again.