I've got a 97 f350 all stock, died this morning on the way to work just like someone shut the key off. Wait to start light and tach seems to have quit working. Check engine light came on when she died but is out now. Tried swapping in a new cam sensor with no luck. Thoughts?

 

https://drive.google.com/file/d/0Byb...1qRU1VVGc/view

 

If you have no wait to start light when the key is first turned to the run position, check fuse #22 in the under hood fuse panel. If it is blown, unhook the fuel bowl heater and replace the fuse, as it powers both the fuel heater and the PCM power relay.

 

Unplugged the fuel heater and changed fuse 22 which was blown, no wait to start still. Trying to find the red power wire for the computer

 

Is the fuse blown again?

Also check fuse #9 underhood.

 

Fuse 22 isn't blowing again, and fuse 9 is good

 

Check the PCM power relay. I **THINK** relay assignments are in the Fuses section of the owner's manual.

 

Sure you unplugged the fuel heater wire? Second down from top on drivers side. Spade type of connector, real hard to unplug. Sometimes you can't see fuse 22 blown, need to verify with an ohm meter.

 

Does anybody have a picture of which wire in the plug is the one that Powers up the pcm? My fuel heater is unhooked, and I confirmed the fuse good. I tried swapping in a known good pcm from another truck with no change. I also tried hooking up a snap on scan tool but it says it's unable to communicate with either pcm. I think my issue is still power not getting to the pcm, but I'm not sure exactly which wire should have power and I haven't been able to find pinout of the plug

 

Also does anyone know where to get another diode? I figured just replace it for stupidity sake

 

 

Check for power at the red/green wire, small terminal, on the GP relay. That's the same circuit.

Boneyard, maybe, for the PCM diode.