Guys,

Need a little help here. I have 2001 sohc with 2004 harness. have the pats programmed working fine. Starter, and fuel pump work. But I have no power to the coil pack. I checked the PCM relay and fuses all good. I keep seeing something about a PCM relay diode but with the 2004 harness it seems as if they took out of the battery fuse panel under the hood. If that could be the issue where in the world would it be?

 

I show the Red wire at the coil pack being connected to the Red wires on the fuel injectors and the Red wire on the IAC Valve, so they all share the same 12volts in 2004 wiring

The PCM Diode was moved from the engine fuse box to the Smart Junction Box(in the cab), in 2004, but it only activates PCM Relay, in 2004 and up coil used 12v from PCM relay/fuse, it didn't in 2003 and earlier

For 2003 and earlier the coils 12v did not go thru the PCM Diode or PCM Relay it came from a fuse in the cab
In 2001 that was fuse #19 25amp, key on power, it also was the power that activates the PCM Relay, it's not the PCM Fuse

So you have a couple of options
But with the 2004 wiring harness I would use PCM Fuse power for the coil, so splice the Coil's Red wire to the IAC Valves Red wire, or fuel injectors red wire
Cut the coils red wire so you don't back feed the 12v to where ever that goes now.
Then tap either the IACs red wire or fuel injectors red wire

In 2001 the coils red wire ran to the engine fuse box and was connected to the power side of the Diode, the wire from fuse #19 in the cab, the Load side of the diode went to PCM relays coil to activate it
You could try tracing it to there, but not sure where 2001 wiring would start and 2004 wiring ends

And check the pins on the large connector for engine wiring, could be coils 12v pin is just not connecting inside

 

Thank you for the suggestions. The 2001 wiring is only on the engine harness. The 2004 is everything else. I checked and had power to PCM relay, and fuse. I will try a temp splice to the IAC valve to see if that works. Let you know when I do.

 

Ron,

OMG thank you so much. I ran a wire from the IAC valve to the coil connector and it worked. Started right up and ran.

Thank you again

Greg

 

Ok guys. Got the engine running thank you Ron D. Here is next issue. This is a 4.0 sohc with manual trans. I was running the truck and heard a squealing noise. Went around to the passenger side of truck looked under and heard it coming from the bell housing and saw sparks flying. What in the world would cause that?

 

Wrong starter motor
Or starter motor is engaging when it should be off, i.e. wiring to starter circuit is wrong

 

its a brand new starter for that motor. I will check to see if the starter is still running.

 

Manual and automatics use different starter motors on the 4.0ls if memory serves

 

Ron,

this is the one I got. I talked to a coworker. he suggested possibly checking the throw out bearing. Does this sound like a possiblilty?

DB Electrical SFD0049 Starter (For Ford Explorer 4.0L 97 98 99 00 01 02 03 Fits Manual Transmission Models)

 

Well Ron I figured out my issue.Turns out operator error. Did not know that ford made to different shim plates for the 4.0. I had the auto plate in. sparks and noise were back of fly wheel rubbing. Found the right plate and should fix issue. Thanks for your help.

 

Good work

I didn't know that either

Thanks for the update and good info