I appearantly have the wierdest '86 ever mfgd.
Mfg. date 6/86 which I would assume is toward the end of the year of prod.
The only explanation I can think of is someone put an '87 6.9L in this truck, as it's definitely a 6.9L, and hooked the installed glow plugs and controller to the old system? It's had a hard life so that's possible.

It has the '86 glow plug system except it has the ZD-9 "bullet point" glow plugs and the controller WAS right behind the CDR attatched to the intake manifold. I pulled it off and threw it in the junk pile and I haven't leaked any coolant so it must not be an '86 style. I don't know for sure though as I've never owned the "old style" but everything on the fenderwell is the "old style".

The system is not like my '94 but it is a factory turbo so it's the "new style" and I'm assuming they relocated some things to fit the turbo on.

NONE of this really matters because I have manual glow plugs on it now but I'm still curious. I keep reading how it "should have" been but it wasn't that way.

Two more things: the glow plug wiring LOOKS stock EVERYWHERE but who knows. AND I ordered the Beru/Motorcraft glow plugs FROM the local FORD dealer FOR an '86 and I automatically GOT the ZD-9s.????????????

 

Look at the drivers side head, back at the firewall pointing straight up close to the intake manifold.
Do you see a square headed pipe plug?

On the stock 86 system, this would be screwed into that hole.
And the wiring connector is on the glow plug controller in this picture.



No removing that controller without a coolant leak since it screws into the coolant jacket in the head.

On the passenger side inner fender behind the battery, going from the fender in you have a voltage regulator and then the glow plug relay.



Big orange wires with white stripe are power to the glow plugs.
Black wire under the orange wires is the wait to start light connection.

Black small wire on left is a ground. (Can't reaaly see this connection)

Red wire on large terminal to battery (Also blocked in picture)

Purple wire on small right terminal is from the glow plug controller in the drivers side head. (Has been cut and green wire spliced in in the picture)

Right now I can't remember if the 87 engine harness will plug into an 86 chassis harness.
I know the later 7.3 harnesses will not plug in.

 

OK finally got out and looked at it.
There IS a pipe plug in that hole. Looks like it's always been there or at least for a LOOOONG time.

 

The 86 glow plug system was a headache as soon as it started having problems.

I am a master electrician, and the trouble shooting method for the old system left a lot to be desired.

Don't get me wrong, the system was an ideal system as long as it worked right.
If the coolant temp was warm enough, no wait to start light and no heating the glow plugs because they were not needed.
Glow plugs lasted a long time.

My main issue was it is a nightmare to troubleshoot.
And the biggest thing, when the controller starts to go, it starts turning the glow plugs on when they are not needed, which burns them out.
The indicator is so low on the dash, during the daytime you never see it come on and you may or may not see it at night.

That was my reason for going manual, and I have never regretted it.
Well on time someone went to move my truck, and did not know about the manual glow plugs which cost me a starter, but that was my fault for not removing the keys on a jobsite.

My bet is the original glow plug system failed and a previous owner swapped in the new style system long ago.
The new style system is much easier to troubleshoot.

 

The only part of the "new" system is the glow plugs themselves though.

 

The part bolted to the intake manifold right behind the CDR was also part of the new system.

Definitly sounds like a hack job somewhere in the past.

How was power supplied to the relay mounted on the intake manifold?

I could wire up a setup to still use the stock relay mounted on the fender, but it would have to have a wire running from the new style controller white terminal to the old style relay ground terminal.

Probably would not work exactly right, but it would work.


The turbo engine harness is a little different than the NA harness.
The turbo harness moves the controller/relay over to one of the rocker covers, passenger side if I remember right.
The NA version mounted the controller/relay on the intake manifold right behind the CDR.

 

I don't remember how it was wired exactly as it's pretty much all gone but it DID have the relay right behind the CDR but I removed it.
My turbo truck has the relay on the rear of the passenger side valve/rocker cover like you described.

I took it over to my Dad's shop and had him tell mre how to re-wire it. We used an electric golf cart solenoid which is kind of like a fender mounted Ford starter soleniod. It was pretty cheap to do and I definitely like it that way.

Knowing how and WHEN the factory controller is supposed to cycle the glow plugs I think will make mine last longer (I put in 8 new Berus when we wired it, 5 were bad). If I didn't know how the controller normally cycled the glow plugs I would probably be using them more than I actually need to.

Thanks again for the help. There is no logical reason why I should care how this system is put together as I'm not even using it antway, I was/am just curious. So it's pretty much a waste of your time. I can't figure why when I ordered the flow plugs from Ford he gave me the ZD9s, maybe he didn't even look them up, just got me the ZD9s out of habit. AutoZone gave the older style in Bosch brand when ordered for an '86 but I decided not to use them even if they had been the right style and took them back.

I'm definitely leaning towards this motor being an '87 that was swapped in and they used the half of the harness that was on the motor and the other half that was in the truck and grafted it together. I don't know if it EVER worked because it wasn't when I bought it.

As a little aside: this truck came from the area of Oregon where the History Channel show AXE MEN was filmed.
It went through the floods there and was hit by a mud-slide. You can see where mud and trees/logs hit it. The previous owner told me they just drug the logs that were piled around it, against it, over it whatever they had to to get it out.
It doesn't have a straight body panel on it but the basic structure is sound. The passenger side looks like the sheet metal was just pressed over the skeleton of the truck. It's caved-in everwhere it could, only the support structures are still holding it out. I figure that was the up-hill side that took the brunt of the slide.
I pulled all of the old carped etc. out of the interior and the "troughs" under the sill plates were packet with mud/silt. It didn't get up into the seats or into the rear end and transmission as far as I can tell but did get into the brakes.
Tough old truck.

 

The only time I have invested is how long it takes me to type my replies.
Glow plug systems are engraved in my memory after I swapped mine out to a hybrid system.

93 NA engine harness running the 86 relay feeding it with manual control.

For what it is worth, the new style controller has the old style relay mounted on it.
Remove two nuts, unhook the wires and you have a relay that will bolt right in place and wire up like the original did.