I drive '91 f350 7.3d with some glowing problems. When I turn the ignitionkey I can here the gp relais flipping over but after about 4 sec it goes crazy, it just keeps flipping for about another 4 sec. Yesterday I tested the relais with putting direct voltage on the controlwire which resulted in the same behavour as with the ignition key. As long as it got batterypower it kept flipping bank and forth.

 

The ignition terminal should have battery power when the key is turned to ON.
The white control wire terminal goes to ground to activate the relay to turn the glow plugs on.
You may have fried the solid state controller if you put battery voltage to the white terminal while it was trying to turn the glow plugs on.
If you put voltage to the ignition terminal, you should be OK because that is what the ignition key normally does.
Also the glow plugs should never heat for more than about 10 seconds constant on or they will fry. They are white hot after 10 seconds of constant on when they are all working. The rapid clicking after 4 seconds of heating is because the good ones are white hot after 4 second of on due to the extra voltage because some of the plugs are burned out.


Test that by clipping the ground clip on an automotive test light on the positive battery terminal, remove the wire from each glow plug and touch the tip of the circuit tester to the connector on the glow plug. If the tester does not light, the glow plug is bad. Repeat for each glow plug.
Bad glow plugs should only be replaced with Motorcraft/Beru ZD9 glow plugs. Autozone has them for 9.99 each.

 

I still don't get why the relais is rappidly turning on and of after the 4 sec, you should say that if the glowplugs are heated the relais just turns of.
Can you tell me which wire I have to juse to make the glowing manual, yesterday I spend about 1,5 hours to make the glowing manual after I was finished I realised I put the manual wire on the place of the ignition wire so the only thing changed was that instead of turning the ignition on I now have to flip the switch to start glowing.
I gave it try in this way and it started right up, the day before it wouldn't start by glowing on the ignitionkey.(Strange but true)

 

Try this link: http://www.members.shaw.ca/k2pilot/G...%20diagram.jpg

saigon

 

I don't get the idee of the diagram, is the diagram the same as the picture. If it is this is the way how it is at the moment. As I see it you can now manually start glowing but you still can't control the glowtime.

 

Exactly Johnny,
This wiring is to use with a manual switch only,your glow plug controller will be bypassed with this system so you have to personnaly control the glowtime.I have been using the system for over two years now because my controler was coming on while I was driving and my glow plugs would all burn out at once,I removed the controller since then!I just leave the plugs on 5/6 seconds and release the switch and start the engine, I do not give any afterglow and I have had no problems starting even in cold weather!
Sagon

PS. personally I prefer Bosch glow plugs

 

I put my new wire on the place that says IGNITION KEY in the first picture and removed the original wire in the first picture. When I switch in the glowplugs the relais still glows for about 4 sec and than goes crazy for as long as I leave power on the controller.

P.S. That you prefer Bosch is because we live in europe I think.

 

Well maybe you have a bad glow plug controller, I am not to familier with the model you have, mine is a 1986 model without the solid state controller!For the Bosch glow plugs I buy them at rockauto.com in the US!I believe they heat up faster and last longer than the others!

 

i've been going thru the same trouble & disconected the white ground wire at the controller but when i hooked up a + feed to the terminal the new push to start switch stayed hot on both sides then discouvered that the white was ground so ran new push button to ground & plugs now only stay lite when button is pushed.

 

I had the same problem, twice now. The first time, the glow plug relay cycled on and off somewhat rapidly when I turned the key on. It was two burned out glow plugs, one on each side of the motor. The second time it happened, it would cycle after the WTS light went out. It was one glow plug that had a poor electrical connection between it and the intake manifold. I removed it, cleaned and lubricated the threads and the problem went away.

Test all of your glow plugs with an ohmmeter. They should read less than 2 ohms.

 

Johnny have you checked the glow plugs?

The ignition wire has battery voltage on it when the key is turned to ON.
To make the 87 thru 94 solid state relay manual, you have to remove the white wire, run a wire from that terminal in to a push button that grounds the wire to activate the glow plugs.

10 seconds max time to hold the button down, less when the weather is warmer than 40 degrees or above.
If you have burnt out glow plugs the 10 seconds will toast others till you have none.
4 burnt plugs doubles the power to the remaining 4 plugs, so they will toast at 5 seconds.
The resistance change as the plugs heat is what the solid state controller senses to time the heating cycle, if you have burnt plugs the resistance changes faster due to more power being sent to the remaining plugs. This is why the plugs cycle faster when the plugs burn out.

First thing to check when the plugs cycle faster than normal is to see if you have burnt plugs.
Second thing to check is the black grounding wire is making good connection.
Siagon sent you a diagram of the 83 thru 86 glow plug system, it is an entirely different animal than what you have.
Corrosion on the connectors can also cause glow plug problems.

Also when you say it started with the wire you installed to make it manual, but not with the ignition switch. The next question is do you have voltage at the ignition terminal when the key is on?
There is a connector in the engine wiring harness that connects to the chassis harness near the oil dip stick. It has about 12 wires in it on your model. Pull it apart and check for corrosion inside the connector. The two big wires are power to the glow plug relay, the smaller ones are the ignition, oil pressure, water temp, water in fuel, filter restriction, high temp light and a couple more I do not remember right now.

 

Now it all starts to make sense to me, so if I make a pushbutton on the white ground wire I'm in controle of the glowingtime.

In first I will clean up all of the connections on the controller and plugs and try to give it a go.

Thanks for the quick reply's and I will keep everbody informed on my discoveries in the wonderfull world of glowingsystems.

 

Today I took of the white wire wire and replaced it by a ground wire with a pushbutton and after 6 sec. it started right up the first time.
But when I now turn the egnition key the "wait to start light" still turns on but it won't start glowing untill I push the button.
In first is this normal and second is it possible to let the '"wts" light turn on only as long as you push the groundbutton. (In that way I can see if it's glowing or not.)

 

Well,I dont know much on your model but what if you spliced your wts light wire,the one behind the dash ,between your pushbutton and the actual wts light bulb?When you push the button it would energize the bulb as long as the button is pushed in!
Saigon

 

johnny thats what my 90 does, turn key and wts lamp comes on but test lite on gp's shows no power until button is pushed.