Madpogue.
Conector disconnected: Measurements at glowplug terminal where wire connects to glowplug terminal
A. Red/green wire
Key on, engine off: O volts connected to ground:
B. Pink orange:
Key On , engine off: Infinite resistance
Key OFF: Infinite resistance

Connector connected:
A. Red/green wire
Key on, enine off: 12 plus volts at terminal
B. Pink/Orange
Key on, engine off: 12 plus volts

With Key on and measuring voltage at the female end of connector I get 12 volts for R/G and 1.3 volts for pink orange wire. This is disconnected.

 

Hmm, red/green should be supplying voltage TO the coil circuit from fuse #22; it shouldn't be getting it FROM the relay.

That second set of tests, with the connector plugged in - did you test those voltages with the key OFF? If not, do so and let us know the results.

One other thing to try - disconnect the connector, turn the key to RUN and look at the dash for the WTS light.

 

One more thing:
Next to the radiator I have a grounding stud and attached to it is four wires.
1 comes off the battery
3 go into a wiring harness.
I ohmed all the wires disconnected from the frame back to a negative battery ground and got good continuity for every wire except the largest black/white wire. (the heavist gauge wire). Shouldn't that also show continuity back to the negative battery post? It doesn't!
With key off.

 

Disconnected from the frame, no, it wouldn't show continuity to the battery neg. That wire is the ground _for_ some component (possibly the PCM or IDM?), through the frame back to the battery. That stud is what provides the connection to negative ground.

 

I don't get. When I check continuity on the other 3 wires back to the battery negative post, I get continuity, less than 5 ohms. But the big black white one, I don't.

 

Those other wires might be for components that have some other ground path.

 

I didn't read the whole thread but 18 pages later and still no start?

 

When connector is disconnected, there is no WTS light with key on. With Key off, there is no voltage at the connector, either pin.
You might have misread what I posted but the r/g wire with the connector disconnected has no volts at the glowplug terminal, so it is receiving its voltage from the connector.
I just don't understand how I keep getting 1.3 volts at the connector through the pink wire.

 

AhA, here's what I'm thinking is happening - the coil circuit supply wire (red/green) should be hot as soon as you turn the key to RUN; it should also turn the WTS light on. Even if the glow plug relay connector is unplugged. But it's not. What I'm suspecting is happening is, that coil circuit is getting energized FROM the relay, probably from the main "big terminal" wire (the "contact" circuit) from the battery. That's why you get voltage on the r/g wire only when it's connected, and that's also why you get the WTS only when it's connected.

So that points back to the fabled maxifuse #22, and the fuel heater. Double-triple-check that fuse. Test it with the meter. Look at how it connects. Also, disconnect the red/green wire from the fuel heater on the fuel bowl. Replace the fuse if necessary. Then see if you get the WTS with the key on and the GPR disconnected.

But if this turns out to be the case, I'd say the GPR is hosed as well. It should NOT be putting voltage to the coil circuit from the contact circuit.

 

Okay, I checked fuse 22 and it is good. I cleaned the contacts on it with a wire wheel on a drill and inspected it. I noticed it is a little bent in the middle where it must have gotten hot once before. Anyway, with the glowplug 2 pin harness disconnected and key on I get a WTS light for a couple of seconds. But I drove the truck 15 miles a few minutes ago and that makes sense.
When I drove the truck I disconnected the hot wire that goes to the glow plug relay. Truck ran fine for 15 miles, not once did it stutter or did the CEL come on. Maybe, and I say that with a Capital M, because sometimes it goes quite a while before I get the CEL, but maybe we are getting somewhere. But why would the glow plug relay cause the engine to almost not run and get a CEL?

 

So is this the first time that engine has started since the no-start condition began?

Again, long thread, lost track, but did you ever get the code(s) associated with the CEL? I'm just speculating here, but with the CA trucks, the PCM monitors the glow plugs, so if that connector's off, it's possible that it can throw a code that would only be seen on a CA truck.

Is the shunt in place on the output "big" terminal on the relay?

 

I just had the codes read on Friday.
Here is what they were.
1280
235
472
1211
198
113
603
Some of these are because I purposely disconnected some of the sensors and ran the truck to see if it would still stumble.
I have had the truck running for quite a few weeks now, but just cannot get rid of the CEL light. When it comes on the truck stumbles. For a few days it would come on and the truck would run fine.
The guy who read the codes specializes in powerstroke engines(he had a ford code reader) and he seems to think I have a problem with my engine harness or the IPR/ICP. He thought the truck sounded like the IPR/ICP was not working properly. He did say that at idle the IPR duty percent was 16 and he thought that was high.

Those two wires from the glowplug relay come off the two small terminals and go to the connector. The wries then go into the engine harness. I don't believe the pink wire should have 1.3 volts with key on. Actually my IPR connectors has 0.33 volts with key on and it should be below 0.25. So, I am still thinking a short somewhere, but maybe the glowplug relay is sending some stray voltage back to the PCM through the connector. Tomorrow I will start the engine with the connector disconnected and see what happens.
I am not sure what shunt you are talking about. The big wire that goes to the glowplugs runs into the harness as I recall.

 

Any comments on the codes?
Need new ICP?

 

I'm not sure what to tell you. Did it run any different with the icp unplugged? Any oil in the icp wire plug?

Have you done the wiggle test on all the wiring?

Bump up top if nothing else.

 

No oil in ICP.
It doesn't run any better with ICP unplugged.
I've wiggled every wire I can find.
I even took apart the PCM harness from the PCM to the valve covers . Even had the fuse box upside down.
I have a new ICP on its way.