Could some one tell me why my wait to start light starts coming on after the truck is started? It seems to work right when you first start it in the morning, truck fires right up, then a couple miles down the road the wait to start light starts coming on and going off. Any help would be appreciated.THANKS

 

With an 85 there are problems with the system controller sometimes.... Dave will help you I'm sure when he see's this post.

If you enter your truck info on your initial post until your allowed to do a signature it will help us immensly....... thanks

 

Coolant temp sensor for the glow plug system is shot.

That is a common way for them to fail.

The sensor is around 100 dollars from Ford, if they still have them.

I converted mine to manual many years ago.

The sensor is located at the rear of the engine, round and about 2.5" across as I remember.
It screws into the back of the head.
It has been so long, I do not remember which head it was in.



The purple wire goes to the controller, unplug it after you start the engine.

To convert it to manual control, run a wire from that terminal to the inside of the cab.
Attach it to a momentary switch on one terminal.
On the other terminal attach a wire that is hooked to a power source on the other end.
I like to use a power sorce that is not hot when the key is off, that is a sort of safety if kids ever play with switches in your truck.

To operate the glow plugs, turn the key to ON.
Push the switch for 10 seconds.
Start the engine.

You will also find you do not need the glow plugs for a restart for several hours after the engine was up to operating temp, save the glow plugs for when you need them.

I almost forgot, the glow plug relay in the picture is located behind the passenger side battery, down on the inner fender well.

 

just a quick question on this one....could this also be a problem on the '90s as well and will going to a manual switch on the glow plugs solve that for me?

speedrdr

 

87 and later engines use a different glow plug system.

 

Dave S, I was looking at the pic you posted and took look at my '90. they look similar( except mine had about a million wires on it). will the same instructions you posted for the 85 work for converting to a manual glow plug switch on a '90 or am i chasing a rabbit here?
speedrdr

 

Thanks for the info, also should have said my truck is an 85, with a later model 7.3 non turbo engine. dont know if that makes a difference. Is there any way to find out what year engine it is, or does it even matter? only reason i ask, is every time i go to buy a part for it the guys a the parts store always ask. THANKS

 

This is an 87 and later glow plug controller.

The early system had spade terminals on the glow plugs. (ZD1A glow plugs)
Uses a controller that screwed into the coolant jacket, I do not have a picture of it or the location.
The relay is mounted on the inner fender well.

The late system has bullet connectors. (ZD 9 glow plugs)
The controller uses resistance feedback to time the glow plug cycle and is mounted under the relay.

On the late model system, power is provided to the relay by the ignition terminal of the relay.
To convert to manual glow plugs, you use the momentary switch to provide a ground connection to the white terminal of the relay.
Wiring is the same except you hook the second wire from the switch to a good electrical ground instead of hooking it to a power source.

Operation is the same, key ON.
Push the switch for 10 seconds.
Start the engine.

Big R,
You will have to determine which system was used when the engine was changed.

When I did my swap, I already had manual glow plugs for years.
So I bought a 93 wiring harness for the engine and used the late style glow plugs.
But I am still using the original glow plug relay that came on my truck.

I am using an 85 engine.
A 94 7.3 turbo fuel system.
A 92 F350 4x4 front axle.
A 96 F 450 hydraboost brake system.
Several other parts are not even from a Ford truck line.

I did have a good laugh when I took my truck in for an alignment the last time.
The alignment guy at the local Ford dealer had a priceless look on his face when he tried to install an 86 F250 outer tie rod end on the 92 Dana 60 front axle.
The one in his hand was 9" long.
The one on my truck was several feet long.

Other than the look on his face, I thought it was a bit scarey he could not tell the difference between an IFS and a Dana 60.
After I got him straightened out, all was well.
My truck drives like a 92 F350 just like it should.

 

thanks dave s. much good stuff you tell me here. i'm not that knowledgable about diesels but am learning lots from all y'all at the FTE site. thanks again.
speedrdr

 

I have only owned one diesel 1985 F350 6.9L.Dose every diesel engine kick down after it warms up?I have always waited for it to kick down before i drive off.

 

Dave S. I wish the local diesel mechanics here in Knoxville,TN had 1/2 the knowledge you do about these trucks. Most try to tell me to upgrade to something newer, but why pay forty grand plus just to have a truck like everybody else. You just dont see to many people driving a 1985 forest green F350 crewcab 4x4 here in Knoxville. And the best part is, I only have about five grand invested in the truck so far. These new trucks may run off and leave me pulling most hills, but a least i only have one mortgage to pay at the end of the month if you know what I mean. THANKS and GOD BLESS

 

. These new trucks may run off and leave me pulling most hills, but a least i only have one mortgage to pay at the end of the month if you know what I mean.
THANKS and GOD BLESS[/QUOTE]


amen to that and its real satifying when you get to pull them out of a hard spot or ditch

 

So bring me a little pile of money, I can build you one of these and install it in your truck.

A little pile is about 1 years worth of new truck payments, but you get to save the taxes and insurance payments the new truck would also require to buy fuel and tires with.



Some of those new trucks are going to feel bad after you do that though.
The owner of a new 50,000 dollar truck is usually not very happy when a 20+ year old truck passes them by.

 

I wish you lived near by, and i had the money right now, I would definitely take you up on the offer. That 6.9 would for sure make me smile. One of my friends has a new duramax, and all he does is brag about that truck. I would love to leave him in a cloud of black smoke. maybe one of these days.

 

Empty Duramax trucks are hard to catch, even for me.

But if you can find one with a real load on it, they are not so tough.

I toasted one when I had about 3 tons of stone on mine, he had a cube of block on his.
After I blew his doors up a hill, he would not even pull up beside me at the next stoplight.
When the light changed, I was expecting a hole shot move since he was way back behind the car in front of him, but he stayed way back.