franklin2

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Actually I just realized if I really got excited about It I could just cut that connector out completely and splice all the wires couldn't I? The connector is just there for convenience if I'm not mistaken.
Getting rid of the factory plug in poor shape is a good idea. But I would not permanently splice the wires together. I would try to put some sort of disconnect back in place. I say this, because when I replaced the valve cover gaskets, I appreciated being able to take this plug apart and get the wiring out of the way. You will also notice most of the wiring to the top of the engine goes through this plug. So if you ever had to pull the engine, disconnect this plug and it would be much faster to get the engine out of there.

I would look on Amazon or somewhere for some sort of universal wiring plug that you could retro fit. How many wires are there? A 6 or 7 wire trailer plug setup would be better than nothing.

On your power wire testing, the best way to test the heavy wiring is with two people. You have the meter and are holding it on the wire to be be tested with it set in volts, while someone else triggers the glowplugs. The voltage should drop pretty far if the glowplugs are working, usually 8 or 9 volts. Batteries are different, each truck is a little different, but if the glowplugs are working, they draw a lot of power.
 

IDIBRONCO

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I would try to put some sort of disconnect back in place. I say this, because when I replaced the valve cover gaskets, I appreciated being able to take this plug apart and get the wiring out of the way.

You will also notice most of the wiring to the top of the engine goes through this plug. So if you ever had to pull the engine, disconnect this plug and it would be much faster to get the engine out of there.
YES! Both of these are VERY good reasons to NOT permanently splice those wires together. It may be easier to do now, but will be much more trouble in the future.
 

rorykillam

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That's what I was thinking, I will look around for a connecter plug somewhere to replace it. I can't imagine it will be too hard to find.

So sadly I did not get to do as much trouble shooting as I was hoping today. But I did make some progress, I rigged up a temporary manual GP switch in the cab. Low and behold it forces the GP relay to give power to the glowplugs and the truck starts like a charm now after holding the button switch for around 8 seconds!
Took about two seconds of cranking before the truck started, it was a little rough for the first 2 seconds of running but I think that's because I had disconnected one of the fuel return lines while messing with wiring.

What I did was I took a 14ga wire with a ring fitting (not sure the technical name lol) and put it on the terminal of the GP relay where the white wire goes. From what I understand the controller grounds the terminal via this wire which opens the circuit to the GPs. So I ran a 14ga wire into the cab from that terminal and connected it to a push button switch, then wired the other side of that switch to the chassis of the truck. So when I press the button it grounds the relay manually.
If I'm not mistaken this should mean one of three things:
1. The relay is not opening the circuit on its own properly which means the relay is bad.
2. My controller ground is not good enough (which I doubt but it is possible)
3. The controller is not heating properly because there is resistance somewhere, I just can't imagine where the resistance is.

One side note that I don't think is important but I will share on the off chance that it is. I Ohmed the terminal on the GP relay where the white wire attaches, I put one of my multimeter leads on the terminal and the other on my negative battery post and it read 6 Ohms (before I wired in the manual switch). Not sure if that means the relay is resistive or not...

I appreciate all the advice, I can at least start the truck reliably now without cranking the starter too long lol. I might take a break from this while I do some other maintenance on the truck.
 
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rorykillam

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Also didn't get a chance to advance the timing on the pump, I might check it out after work sometime this week. If I do I'll be sure to let you all know how it goes.

A little off topic but I have heard some people recommend running ATF through the injector pump and letting it sit over night to help clean out the internals on older pumps. Any thoughts on that?
 

IDIBRONCO

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Also didn't get a chance to advance the timing on the pump, I might check it out after work sometime this week. If I do I'll be sure to let you all know how it goes.
If your truck is starting fine now, you don't need to bother. You can if you want to, but it's not a bad idea to have the timing checked since you know nothing about the condition of the pump.
A little off topic but I have heard some people recommend running ATF through the injector pump and letting it sit over night to help clean out the internals on older pumps. Any thoughts on that?
It's not a bad idea.
 

MadMac

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I could just cut that connector out completely and splice all the wires couldn't I? The connector is just there for convenience if I'm not mistaken.
Hard lessons from work and play: separate diagnosis from solution. Unless I would implement the solution anyway, I stick to building things to confirm a diagnosis before trying to ideate the right solution. Just like the remote starter (you might even be able to use one to test), I’d bypass the wire to see if that is actually your problem and then figure out your solution. This is also an implementation of the “known good” principle. Tough problem you have, wishing you the best.
 

franklin2

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The relay for the glowplugs works the same as the starter relay. Except they wired it backwards. When you turn the key to start, you send 12v to the small terminal on the relay, and the other side of the relay is grounded through the mounting feet.

On the glowplug relay, it does not ground through the mounting, it has a separate terminal for ground. When you turn the key on, 12v is sent to one of the small terminals all the time. But there is no ground on the other small terminal, so it does not click and send power to the glowplugs. What you are doing with the white wire is giving the relay a ground to complete the circuit, the relay clicks and sends power to the glowplugs. Normally the "brain" in the controller grounds the terminal, and makes the relay click and sends power to the glowplugs.

Obviously the power wiring is good, which includes the plug we were talking about, the glowplug relay, the glowplug wiring and the glowplugs. What is bad is the decision making of the brain.

Ford has some good ideas, and then some not so good ideas. Some people have good luck with the controllers, though they spend time and money keeping them that way. I got tired of messing with it all the time, and converted to the manual switch, and never looked back. My truck always starts in most any kind of weather, that was priority.

The original controller is just too sensitive to older wiring and blown out glowplugs. With a manual switch you can tell when you have one or two bad glowplugs, you will have a couple of dead cylinders for a few seconds when it starts. Bad glowplugs happen all the time, but it can't be a show stopper for me, I need the truck to run, and I can replace the glowplugs later. With the original controller, one bad plug and the engine is not going to start.
 

rorykillam

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The relay for the glowplugs works the same as the starter relay. Except they wired it backwards. When you turn the key to start, you send 12v to the small terminal on the relay, and the other side of the relay is grounded through the mounting feet.

On the glowplug relay, it does not ground through the mounting, it has a separate terminal for ground. When you turn the key on, 12v is sent to one of the small terminals all the time. But there is no ground on the other small terminal, so it does not click and send power to the glowplugs. What you are doing with the white wire is giving the relay a ground to complete the circuit, the relay clicks and sends power to the glowplugs. Normally the "brain" in the controller grounds the terminal, and makes the relay click and sends power to the glowplugs.

Obviously the power wiring is good, which includes the plug we were talking about, the glowplug relay, the glowplug wiring and the glowplugs. What is bad is the decision making of the brain.

Ford has some good ideas, and then some not so good ideas. Some people have good luck with the controllers, though they spend time and money keeping them that way. I got tired of messing with it all the time, and converted to the manual switch, and never looked back. My truck always starts in most any kind of weather, that was priority.

The original controller is just too sensitive to older wiring and blown out glowplugs. With a manual switch you can tell when you have one or two bad glowplugs, you will have a couple of dead cylinders for a few seconds when it starts. Bad glowplugs happen all the time, but it can't be a show stopper for me, I need the truck to run, and I can replace the glowplugs later. With the original controller, one bad plug and the engine is not going to start.
Yes that seems to be the case, it's confusing how three different controllers and they all had the same problem. But whatever, it looks like I'm going to have to stick with the manual push button. If I get some more motivation I might do some more diagnosing.
Thanks for the help everyone! I really wish I could figure this out but it looks like I'm at the end of ideas short of just replacing the controller for a 4th time lol.

Side note for those who installed manual buttons, where did you put them? I currently have popped out the panel in the dash where the WTS light is and snuck the wires through there and through the firewall. So I just have the panel and the button hanging out of the dash hahaha
 

franklin2

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There is a little cubby hole underneath the WTS light. I took and made a panel with screws that covers that cubby. I then put a hole in it and mounted the pushbutton there.

But if you can find a place on the left side of the steering wheel, that would be better. It's more handy to turn the key with your right hand, while pushing the button with your left. I do it, but I have to cross my arms.

I have also been experimenting with just glowing the plugs and then starting the engine, and also glowing the plugs, and then cranking the engine and glowing the plugs at the same time. That is another advantage of having manual plugs. You can glow them much less than the controller did, extending the life of the plugs. On a warm day, after the first start of the day, you do not need to glow the plugs at all afterward. On a cold morning start you can glow the plugs 5 or 6 seconds, crank it a little bit, and then glow them again, and then it usually starts. I think it would be much less stress on the plugs rather than glowing them a full 10 seconds. But you can experiment and see what works best for your engine.
 

Old Goat

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I do pretty much as franklin mentioned above.

I don`t have the Cubby he mentioned. Mine is an 86, and to the left of the WTS light, it is a black flat
small panel I drilled a hole and used a black plastic spring loaded Toggle. It blends in and is not noticeable as it is to the right of the Steering Column.


Goat
 

rorykillam

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Awesome, thanks for the ideas! I am considering drilling some holes in the dash for the button, and I do like the idea of having it on the left side. You're absolutely right about having more control over heating the glowplugs, I think the manual button is growing on me haha.
I'll post some pictures of the button style I'm using when I get off work, I haven't been able to solder it yet. I think I'll have to cut a nickel sized hole in order to mount it.
 

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