Sits one week, no power IP and GPC

[OldIron82]

Good evening everyone.
Went to hop in the 90 F350 (7.3 E4OD ) this evening, and no engagement of the glow plug controller, also no power to the injection pump. Everything was fine last week and now it just sits there completely dumb. Everything else works, and I mean absolutely everything else works. Verified with a test light, when the ignition switch is on, no power to the injection pump and no power to the glow plug controller.
I am sorry if this is a common issue. I am on three hours of sleep. I’ve been up for close to 24 hours. I am just not in the mood for this right now. I guess I could just run a wire from a positive battery terminal to the injection pump and also do the same thing for the glow plug controller to light the plugs but I’ve had enough of this Frankenstein nonsense. This is the truck that I had down to the frame and I did the cab swap on. Everything was fine and now suddenly this just comes out of nowhere.
I need to move a skid loader tomorrow afternoon at the latest and if I can’t get this figured out, I’m going to have to borrow a friend’s truck. Don’t know if there’s a fuse or fuseable link or if the brand new ignition switch at the bottom of the steering column is bad I just don’t know.

It would be worth mentioning, I did have a over charging situation, I had to replace the voltage regulator and that corrected that issue, but it did run after that.

Please help. Thank you, everyone.

 

[Clb]

Sounds like possibly the ignition is not sending out power? Maybe?
So it will turn over but no fuel?
I've got an 88 and 93 fsm if you need anything...

 

[IDIBRONCO]

I don't believe that this is a common problem.
Keep in mind that I'm no electrical expert. Maybe a bad wire or loose connection?

 

[OldIron82]

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[OldIron82]

The wait to start light does not illuminate also. If you look at this wiring diagram that I just found, it appears there is one wire out of that and it makes its way to the glow plug controller, and that is also tied into the fuel cut off solenoid, which I never knew. Does this mean there is a fusible link under the dash somewhere behind the wait to start light that could have burned for whatever ungodly unknown reason?

 

[OldIron82]

Sounds like possibly the ignition is not sending out power? Maybe?
So it will turn over but no fuel?
I've got an 88 and 93 fsm if you need anything...

Correct, turn over.

 

[DirtyWood]

When I bought my '91 it was fine for months and then I started to have an intermittent issue where the GPC wasn't getting power, no WTS light, and the solution was a "loose fuse". Swapped in a fuse that fit tighter and problem solved.

 

[90Ford73]

If everything works but the glow plugs and fss, it might be one of two 20 gauge fusible links by the big connector for the engine harness. It’s on the passenger side inner fender south of the voltage regulator, you know the one. Iirc there’s two wires that are out of the wire loom, that’s the fuse links. If you still have the diesel supplement in with your manual it should say something about them.

 

[DougBoy66]

Check the big plug connection for the engine harness on the driver inner fender. Mine came loose when I was getting things back together and working under the hood alot, I had the same symptoms engine cranks but no GP, no wait to start light no fuel. Good news is if it is that all your problems will be solved easily

 

[OldIron82]

Sure as heck that’s where it was!
The glow plug wires already burned years ago when I had this engine in the cab and chassis dump truck. I don’t know what happened, but apparently the amperage was too great and it melted the side of the plug badly so I just completely broke off the melted part and Cut and join the wires together individually. Willing to bet the next two wires over at least one of them feeds the glow plug controller.

While the key was in the on position, I jiggled this plug and I heard the glow plug control controller click, and the fuel shut off solenoid click. I will look more into it tomorrow.

Thank you for the suggestions everyone!

 

[DirtyWood]

Sure as heck that’s where it was!
The glow plug wires already burned years ago when I had this engine in the cab and chassis dump truck. I don’t know what happened, but apparently the amperage was too great and it melted the side of the plug badly so I just completely broke off the melted part and Cut and join the wires together individually. Willing to bet the next two wires over at least one of them feeds the glow plug controller.

While the key was in the on position, I jiggled this plug and I heard the glow plug control controller click, and the fuel shut off solenoid click. I will look more into it tomorrow.

Thank you for the suggestions everyone!

I came across a forum post where someone had the same problem and when replacing the connector they used a separate one for the two yellow wires that feed the GPs--seems like a good idea.

 

[IDIBRONCO]

I came across a forum post where someone had the same problem and when replacing the connector they used a separate one for the two yellow wires that feed the GPs--seems like a good idea.

As someone who used to make a living by R&R-ing these engines, just splicing the wires together is a TERRIBLE idea. If you have to pull the engine, you then have to fish the entire wiring harness out through the injector lines, return lines, etc and then fish it back in. The separate connector is a MANY times better idea. Not to mention other times when it's nice to disconnect it such something as simple as replacing valve cover gaskets.

 

[DirtyWood]

you then have to fish the entire wiring harness out through the injector lines, return lines, etc and then fish it back in.

I just fished that harness out and am going to rewire/reroute things so the top of the engine is as uncluttered as possible. Hopefully just a DIY glow plug harness. The Banks Sidewinder heat shield at the back of the engine makes fishing out that harness a little extra fun. Sigh, so many mods, so little time.