No Power to Fuel Cutoff Solenoid

[lkrasner]

So I lost power on the highway the other day. No warning, had been running great, just shut right off and wouldn't restart. On a whim, used a piece of speaker wire I found on the floor, and jumped the fuel cutoff solenoid to the battery, and it fired right up. Fiddled with the connector with no luck, so power clearly isn't getting to it. Does anyone have a wiring diagram of the ignition system? I assume it could be the ignition switch (though everything else functions normally, don't know if there is a dedicated pin for the shut off, or if it should just be powered by the same "key on" pin as everything else. Or is there a fusible link somewhere between there?

I'm thinking my best bet is to slap a toggle switch on the dash with a 4 amp fuse and run the shutoff solenoid off that. Is there any reason not to do this?

'94 E-350, N/A 7.3IDI with E4OD

 

[dgr]

This is the generation before yours. I see a feed from the ignition switch to the fuel heater and the shutoff. That goes to two fusible links. Might help. Might not.

If you're going to run a toggle, make sure you run it from a keyed power source.

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[dgr]

I looked again. If your fusible link is dead, you won't have glow plugs, cold advance or high idle. If the feed is bad, the fuel heater also will not have power. If it's only the shutoff, it is the wire feeding it. That's how I'd look at it assuming your gen is the same as there earlier.

 

[tradergem]

I had the same problem awhile back and it turned out the ignition switch was coming apart from the pressure of the actuator rod pushing on it. Since the switch was separating starting at the end closest to the steering wheel the contacts at that end were losing connection first. Take look at the switch and if it is coming apart you will see what I am saying. Good luck.

 

[lkrasner]

I had the same problem awhile back and it turned out the ignition switch was coming apart from the pressure of the actuator rod pushing on it. Since the switch was separating starting at the end closest to the steering wheel the contacts at that end were losing connection first. Take look at the switch and if it is coming apart you will see what I am saying. Good luck.

Interesting. I'll have to start taking stuff apart and check out the switch. I don't want to fix just the issue by putting a switch on the dash and then have the rest of the ignition switch go bad on me...

I looked again. If your fusible link is dead, you won't have glow plugs, cold advance or high idle. If the feed is bad, the fuel heater also will not have power. If it's only the shutoff, it is the wire feeding it. That's how I'd look at it assuming your gen is the same as there earlier.

Interesting as well. Now that it's cold I'll see if the glow plugs kick on when I turn the key.

 

[lkrasner]

Ok, I finally pulled the ignition switch today. It feels fine. Nothing looks cracked. I can actuate it by hand, and dash lights come on and such, but no fuel solenoid, no glow plugs. Going to try a new switch still I guess, but thinking the problem must be down the line.

 

[lkrasner]

Ok, still fighting this. Ignition switch is good. I have power on the 2 red/ green leads coming off of it. However, I found 1 of those wires by the driver side battery in the big bundle, and no power there. Is there a fusible link somewhere inside? I can't get at the wires as they pass through the firewall worth anything..

 

[dgr]

I've never seen a fusible link inside a wrapped bundle.

 

[lkrasner]

I've never seen a fusible link inside a wrapped bundle.

There are 2 Red / light green wires coming off the switch. It appears both of these go through the firewall in the main bundle, but I only see 1 on the other side. I'm just trying to wrap my head around the routing here. The diagrams don't describe physical location much at all.

Behind the battery I saw a factory splice with multiple red/ green wires of different gauges. I cut a little insulation and probed on these wires on each side of the connection, and none of them have power. So clearly it isn't getting from the switch to this point...

 

[dgr]

I don't like the way that Ford organized wiring diagram into functional groups. It doesn't match what we see

I think this thread contains the wiring diagram for your year FSS
https://www.oilburners.net/threads/ive-done-something-and-need-some-help.86371/

Understand I don't have the same year as you. My fusible links are off of the starter solenoid and glowplug relay on the fender. I would be checking at connections. I'd pull on each fusible link. Then I'd trace the power wire from the FSS to the connector over the passenger valve cover and probe there.

You shouldn't need to be cutting back insulation. Test light is designed to poke into what you're testing (and your finger). Sharpen the end if needed.

 

[typ4]

I've never seen a fusible link inside a wrapped bundle.

then you haven't worked on many of these trucks there's two fusible links right at the 12 way connector on the bricknose at least, one of them runs the entire injection pump system.

 

[dgr]

Maybe I haven't. Tried to be clear with that I don't own a bricknose. It's inside the taped up bundle?

Where do you think his problem lies?

 

[Thewespaul]

On your year truck the fusible links will be below the starter solenoid, next to the alternator and over by the fuse box.

 

[I Bleed Blue]

CHeck the big 20 amp fuse under your hood. I had the same thing. Bad ffs and was piping the fuse.