Ford glow plug relay

This is a collections of information relating to: Glow plugs, their relays and their controllers on 1983-2003 Ford Diesel Trucks, Vans and some Excursion models with 6.9 & 7.3 engines. (does not apply to the 2003-- 6.0 liter engine)

The Ford Powerstroke engine is a fantastic engine capable of 400,000 miles if maintained properly. The only mistake Ford/International made on this engine is the glow plug relay and controller. The relays on all engines from 1983 through 2003 fail prematurly. In addition the controller on the pre 1996 engines fail prematurly. These two photos show a severly burnt out relay.  The relay quit working and  brass studs were removed with little force. You can see the corroded contact ring inside which is so corroded it will not allow current to flow and causes a lot of heat which frys the relay housing as can be seen below:

 

To get around the problems with this relay, I have located a relay that seems to last forever.
(See below for more info)

Many people have asked why I can say the relay I offer is  better that others being sold on ebay including Ford's new design. 

Ford has had a lot of problems with this relay over the years and has tried several fixes. This is evident due to all the people buying new relays on ebay. Their latest fix is to enclose the internal contact area with nitrogen gas. This gas is to reduce the deposits from the electrical arcing inside the relay. 

This did not solve the problem, don't know if the nitrogen leaks out or what. I suspect after time the nitrogen just leaks out, who knows. 

I had three diesel Ford trucks with the relay I am on them. One relay was on for 6+ years and I decided to disect it to see what it looked like inside. Below are photos of what I found.

My neighbor had a 2000 Ford F250 and the Ford new design relay failed within the first year. It would not start when it was cold and I gave him one of my relays and to his surprise it solve his problem. It is still on his truck after 8 years. 

These photos show what I found when I disected the 6+ year old relay. HARDLY ANY SIGN OF WEAR!!!

The difference is in the design of the electrical contacts inside the relay I am selling. 

It uses a wiping action on the contacts, which is a very common practice in good design of electrical contacts of high amperage load and these glow plugs require a lot of amps to get red hot for good starting. 
 
Ford uses a rotating copper ring that theoretically increases the contact area by rotating the contact area. There are two problems, one problem is after it rotates 360 degrees you are back on the same burnt contact area as shown in this photo and the two photos above. 

The other problem is that most of the time, the rotating copper ring gets stuck and doesn't rotate anymore. Then it soon craps out as heat builds up as current is passed through the burnt contact area. Other brand relays including the low budget inport relays simply copy Ford's poor design and in less than a year they don't work.  
 
I have disassembled several Ford's relay and the contact area is very nasty looking , see two top photos,with lots of residue from arcing. The wiping action of the relay I am selling actually wipes the contact area clean each time it makes contact. (very clever design!!!!) I actually disassembled the relay that was on my truck for 6+ years there was barely any signs of wear. Included are some photos if you would like to see what I'm talking about along with some photos of the Ford design. Wiper spring on left and contact studs on  right.
 
The company that makes this relay actually developed this relay for the US goverment for use in certain Military applications. I know this since I was having trouble getting my orders filled several years ago and was told all their relay production was going to their military customer(s).

Ford Glow Plug Controllers, another poor design-Check out my solution below:

In addition to the bad design or the Ford relays, the GPR contorllers on the pre 1995 trucks were not very

reliable. The 1983-1987 controllers looked like this  

 

The controllers on the 1988-1995 looked like this

On the 1995 - 2003 the glow plug relay is controlled via the engine computer based on engine oil temp.

Because of the failure rate of these controllers and the unneccary time the newer trucks keep the glow plugs enerigized, I have developed a manual system that bypasses the stock contollers. Here is a photo of the complete kit: 

Here are some reasons to consider my contoller bypass kit

The reason glow plugs and glow plug relays burn out so often is because they are used when they don't need to be used.

The only time you need to use your glow plugs is in the morning on a cold day. But the way they are engineered, the glow plugs come on even when starting the engine when it is hot. This puts unnecessary ware and tear on the glow plugs, the relay and your battery. 

What I'm selling here bypasses all the electronics and allows you do determine when your glow plugs should be energized. So on a cold day you can energize your glow plugs for a longer time and your truck will fire right up. In fact after it starts if it is not running smooth, just reenergize the glow plugs a little longer while the engine is running. Really works cool!!!!!  

The installation is simple and does not require any changes to your existing wiring on your truck except for one minor modification on older 1983-1986 trucks. This mod is simply and involves cutting two wires and crimping on eyylet connectors.

All you do is connect two small wires and mount the push button switch in the cab in a convient spot. I will identify the place to run the wire through the firewall and a easy spot to put the switch.  

What I'm selling is a new SUPER relay (see explanation above),  the new wire harness, the momentary toggle switch and detailed instructions to install the complete system.  The complete installation will take less than 15 minutes and require just a few simple tools.   

Before electronics hit all our cars and trucks, glow plugs were manually energized. The time they were energized depended on the engine temperature. If the engine were cold, you would hold the button for a minute or a bit longer if the engine was really cold. If the engine was warm you would not even energize the glow plugs. Back then glow plugs and their relay lasted a very long time.

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Glow plug voltage

The 6.9 International V-8 diesel used in Ford trucks starting in 1983 used the "fast glow" glow plug system, meaning they were forcing 12 volts through six-volt glow plugs. They can only be energized for 5 seconds max

In 87, they switched to a 12 volt system with 9 volt glow plugs. This same system was used in the 7.3 IDI engines from 88-94. The purpose of using lower-voltage plugs in a 12 volt system was to cause the plugs to heat up more quickly. The 7.3 and 6.0 PowerStroke engines use 12 volt glow plugs.

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Glow plug heating time on 1996 through 2003

. The  glow plug are energized based on the engine oil temp, air temp and altitude: At 30 degrees air temp the plugs heat for 120 seconds; 60 degrees, 60 seconds, 100 degrees, less than 10 seconds.

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Test for voltage relating to glow plugs and relay

Check the voltage drop to the glow plug controller relay terminal. You should have battery voltage with the key off, and the voltage should not drop below 8 volts when the relay kicks on. If the voltage is low with the key off, check the fuse links at the starter relay. If the voltage drops with the key on when the glow plug relay closes, check the connector between the engine and chassis harness at the passenger side fender, and the fuse links.
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Glow plug resistance 

Check the resistance of the glow plugs to ground  They each should  be between 0.6 to 2.0 ohms. If over 2.0 ohms replace the glow plug.  These engines will start with several glow plugs bad depending on out side temp.

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Fuse number 22

If your truck will not start either cold or hot, check to see if fuse number 22 has bown. If blown, your truck will not start. This fuse is one of the maxi fuses This fuse is located in the fuse panel under the hood. This fuse number is based on a 1996 through 1998. Other years may have a different fuse number that does the same thing.  

If the fuse is blown, the fuel heater coil inside the fuel filter housing has most likely shorted out. You can temporally disconnect the oval shaped connector on the side of the fuel filter untill you get a new heater coil.  

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Answers to questions from prospective buyers

Before you buy a new relay  you may want to check and see if your relay has actually failed since your hard starting problem may be your glow plugs are bad.  First try this. In the morning when the engine is cold,  jumper the two large terminals wiht a screw driver for 30 seconds and see if it starts. If the truck is older than 88 only jumper for 5 seconds. If it starts then the glow plugs are good. If it starts then i will ask you to do one more test before you buy the relay from me.
Regards, Chuck

These relays cause lots of cold starting problems and Ford and International plus the import relays don't hold up too well and sometimes are problematic when purchased new.  I also sell a  kit to bypass the controllers on these that are really sweet. I charge $60 for the kit and instructions. click on my other items and read up on the manual bypass setup. I have one on my truck and really like it. Have sold a lot of them. I do have instructions for replacing the one you purchased too.

Regards, Chuck

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Iit sounds like you have it wired correctly. I doubt if the relay is bad, with over 2500 sold, i have yet to find a bad one, but there is always the first time.
Try this. Make sure one of the small terminals is connected to 12 volts through the large terminal going to the battery. Then connect the other small terminal to a good ground on the engine. You should hear a click. Do this with the engine cold and hold the ground for 30 seconds. Then try to start the truck. If it starts the relay is good. If it does not start try jumpering the two large posts with a screwdriver for 30 seconds and see if it starts. If it does not then it is your glow plugs. If your truck is a 83 through 88, don't energize the glow plugs longer than 5 seconds at a time. Let me know how it goes.
Regards, Chuck

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You can rotate the wires 90 deg, either to the left or right. There is no polarity to the large and small terminals. Just get the same number of wires on each of the two large and small terminals,
regards, Chuck

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f you have a 87 or older truck, it is critical you don't energize the glow plugs for longer than 5 sec at a time. 88 and newer you can go as high as 120 seconds. Self-regulating glow plugs are not necessary.
Regards, Chuck

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My manual kit  bypasses everything in the factory setup and all you have is a wire harness, a push button and a heavy duty relay. On 83-87, the glow plugs are 6 volt and only need to be energized for 5 seconds max. Much longer will burn out the plugs. I have sold a lot of these kits for the older trucks so as long as you don't over do the heating of the glow plugs, you will be fine.
Regards, Chuck

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I don't know how to test this the glow plug control unit on the 88-94 trucks. I would suggest you purchase a the manual controller bypass kit from me  and it will solve all your starting problems.
Regards, Chuck

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Customer Input

Hi Chuck
Thought I would let you know that the kit you put together works great.
I had my son in law order it for me on ebay before thanksgiving and I
put it on yesterday.
I had been having trouble starting the 1991 ford F350.  Multiple problems.
Fuel leaking back out of the injector pump was the obvious one.  I
bought your kit to separate the new electric fuel pump from the ignition
and ultimately the glow plug timer.  I now believe a large part of the
starting problem was the glow plugs were not getting the juice they
needed to heat properly.  With the new solenoid it fires up immediately
after I prime it with the electric fuel pump.
The old solenoid lugs were scored and burned like they had had a bad
connection for years.  I didn't open it up but can only imagine the
inside was worse.
Thanks,
jack H.
Walla Walla, Wa

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Chuck,

Thanks for your easy to install relay. I can't tell you how many mechanics I talked to about the cold starting problem. It got to the point where it just wouldn't start at any outside temp. The range of solutions were overwhelming and costly. I decided to google the problem and your site came up. After reading what you had to say about Ford and the problems they had with cold starts I decide to try your inexpensive part. At this point the only way I could get my truck to start was plugging in the block heater and at work that was almost impossible. Your relay part came yesterday( Friday the 12th of Dec.) I installed it today and was amazed that my truck started the first time. I just wanted to say thanks and you must be a genius when it comes to mechanics.

Thanks again.

Earl from Colorado

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Hello Chuck,
           Here's my story from out here in Connecticut.
      I bought a kit from you off of Ebay in August with the intent of using it on my 1987 F350 6.9 diesel crew cab. When I bought the truck 2 years ago it was missing  any sign of a glow plug controller, so this was to be my fix.  I also own a 1992 7.3 idi with a Banks Turbo. The 1992 has a controller but has never started very well. I never even use the truck in winter because it would never start. Three days ago I decided to try to start it before the snow came. No way. So I took the solenoid off the module and tested it. It was dead. Then I took the solenoid out of the box from you and looked at it. I brought it to Napa and they gave me one that looked just like it. I put yours back in the box...I was still saving it for my 1987 6.9.
I put the new Napa one on my 1992 7.3 and hooked up the wires. But it wouldn't work.  I finally figured out that a starter solenoid was different than the factory original.  Positive charge solenoid (starter type) wasn't going to do it.  So I said "I'm sick of this....I am going to bypass this factory mess and use Chuck's kit on my 1992."
I hooked it up as per your instructions, got in the truck and held the switch for about a 12 count. Then I hit the starter.  I was shocked. My truck fired off so quick that it stunned me. And it was 22 degrees here today.  Your kit is great.  No more factory controller for me.  My 1992 has never wanted to start. But your kit changed all that.  Wow!!
    I will soon be ordering another kit for my 1987 6.9.   It doesn't have a controller on it. Just wondering if I need to find a flat spring ribbon to use it on the 1987.  I read about the 5 second rule on the 87 with 6 volt glow plugs. Don't want to burn them.
    Kepp up the good work, your kit is awesome and does everything as advertised.

                                                                   Thanks Chuck

                                                                    Jack

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Hi Jack,

You don't need the "flat spring ribbon", Just limit the plug heat time or get the dual wound plugs.

Regards,

Chuck

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Chuck,

Thanks for your great help.

I installed your solenoid and switch, it works great. I wonder why it wasn't OEM. Guess Ford thinks we are too dumb to remember to use it.

Thanks again,

Dave
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Chuck,

Thank You, Thank You, Thank You! After getting off the phone with you I ran jumper cable from the battery to the large terminal. I waited a few seconds and it fired right up! I then checked the battery cable that was running from the relay to the strarter relay and found a very bad connection at the started relay, it had been covered with electrical tape and looked good until I took the tape off. WOW, what a mess. I cleaned it and put new connectors on it and tryed the switch that you sent me. That van started in 1 second.
I really enjoy being able to manually control the timing of the glow plugs.  

Thanks Again,

Ken 

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