Sorry it took so long to get back to this. I only have a few minutes right now but more later
...A few years ago I replaced the power feed to the glow plug controller >and the trigger wire<. Sad thing is i did not know this inline fuse to the trigger wire also fed power to the cold advance, the fast idle and the injection pump fuel shutoff solenoid.
That's the
same RED/Light Green stripe wire I mentioned in a previous post, being fed through one of those two 20 ga. fuse links I discussed in my first reply. It will be the fusible link with the Red/Light Green stripe wire on the fender side of the fuse link and it's spliced (as is the other 20 ga. Fusible Link) into a single larger RED power wire as I had described.
Where are you tapping the power for this new 'trigger wire' you installed and why was the original replaced? I don't actually see how you bypassed an original problem in that circuit by installing that wire which is why I asked those questions about the replacement wire. What was the original problem and where does that new 'trigger wire' come from (to get voltage)?
It was a 20 amp inline fuse and it burned out causing all this issue. But why it suddenly burned out is still a mystery.
I'll have to do some searching to convert a 20 ga. fuse link to an Amp rating because fuse links are not rated in Amps. I don't have time to do that right now. It doesn't seem like a 20 Amp fuse should be blowing but if I remember correctly, in general, ignition circuits are usually protected with 25 amp fuses in the fuse panels, aren't they? Or with relays in a fuse box under the hood. So that 20-25 amps is probably close to the maximum current that circuit can handle. Should it normally pull that much? Normally? I don't think so.
Because my fuel shutoff solenoid is not making a loud click I plan to replace the top of the injection pump. But for now the rig runs. How long and is it reliable... Maybe... Maybe not...
You should check the FSS with a jumper wire directly from a (+) battery terminal. If it clicks, it should be good, if not would indicate that it is bad, and either way it could be an intermittent problem, a failing FSS OR a bad insulator washer between the base of the FSS and metal on the IP. I think that might cause intermittent behavior. If it grounds out through that insulating washer it could cause a current overload condition in the circuit. I don't want to pretend that I really know a LOT about this specific issue with the FSS but in a similar topic at FTE involving the FSS a missing insulation washer after installing a new FSS was the problem. The original insulator had crumbled and was lost. This was fixed by using a fiber washer from a hardware store. In any case it is supposed to be an electrically insulating washer.
If you need to replace the FSS with the other one you have you could just remove it from the other cover and install it, keeping in mind that the insulating washer might not be in very good condition and might need to be replaced.
When you check the FSS with a jumper wire. ALSO check the voltage at the connector with the ignition key turned to the ON or "RUN" position. If you can get a good connection to that terminal with a test light you might be able to see the light come on from inside the cab. That would indicate that the wiring is good but it's better to use a volt meter to also know what the voltage is. There is a test procedure in the factory shop manuals that should state what the voltage should read at that connector. I might have time to look that up later this evening. I truly am hard pressed to get some very important work done before noon tomorrow and I've been putting it off 'until the last minute' so I'm feeling a lot of pressure right now. I need to get on that as soon as I post this message and get it out of the way.
You could have a problem in the wiring we've been discussing, mainly that Red/Light Green stripe wire.
It would be nice if the problem all along was simply due to a bad insulator on the FSS. I really don't know if that could be the original issue, or the current issue, I've never removed an FSS, nor seen the insulator or the threaded side of a FSS.
I also have no specialised training or education in automotive wiring, which is a specialised occupation. I have related education (electricians school with some electronics 35 years ago) so I'm not intimidated by any automotive wring issues and I just use what I do know to try to help solve problems and I learn automotive wiring along the way.
Your issue seems like a very easy one to diagnose and fix since most of it has been brought into view.
I'll be back later.
