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Hello. I have a glow plug problem. The wait to start light comes on for only a second or two, then the relay starts clicking. The truck will not start, too cold. I have replaced the relay and controller. All the glow plugs are good except one. I seems like the problem is the controller, but it is brand new. Any ideas??? Thanks in advance.
Try plugging the truck in for a few hours before starting it. If it starts easy , that will indicate the glow plug system is goofy. Make sure the wires are on the correct terminals on the controller too. Also, on my older truck, i had much the same problem, the controller would start pulsing before the plugs were really hot. This was due to a bad connection on the controller. One glow plug will make the thing have a hissy fit tho. Be sure to use the Beirut plugs, the champs are crap. Good luck and keep us posted.
try plugging it in if that works you know its your glow plugs, oh did you make sure you have power to the relay and the controller, but yes also check all the connections! and if that doesn't work let me know i work in a diesel shop, and for plugs i recomend ldm's they won't get stuck in the block and you can hold them on for more than just 30 seconds
I should have mentioned - I have bypassed the controller by taking a screw driver across the terminals on the relay, hold the screw driver for 6-8 seconds - and it fires up just fine.
Hey Lord,
Follow this link and follow the diagram, my 86 controller messed up also and even came on while driving and fried plugs regularly, the manual switch will do exactly what you did with your screwdriver, hold the switch 5/8 seconds and fire it up, don't forget tu use a switch like a pushbotton-switch that will pop back to the "off" position.
Saigon http://www.members.shaw.ca/k2pilot/G...%20diagram.jpg
Just the one bad plug can make the difference. Replace it and try it again. Your '87 has the electronic controller, it will not heat full time unless it sences all 8 plugs.
Yea, I replaced the one bad glow plug last night. Still no luck. I am stumped at this point. Brand new controller, brand new relay, 8 good glow plugs. It may be possible that it is not wired correctly??? I cannot find a wiring diagram anywhere, but it is not that complicated. Might have to break down and take it to a mechanic when i can afford it. ?!?!?!?!?!?!?!
Your brand new controller is NFG, the proof of this is that when you shorted the GP relay with a screwdriver, the the truck started right up. Wire up a push-button like Saigon said, and you will be in control.
I wonder if you fried the controller when you shorted out the two posts on the solonoid. I don't know the order you replaced everything, so maybe it doesn't matter. Just thinking out loud.
I don't think shorting the relay would hurt the controller, but from what I have read here on FTE, they are not very reliable. Mine worked fine for several years, but it finally crapped out, and took all the glow plugs with it, so I added a pushbutton. That is why I read this forum, to learn from what others have experienced, Thanks!
The purple wire y'all refer to also has a red wire on the same terminal on the relay in my '88 7.3. I haven't been able to determine what it's for but the controller seems to still affect the realy when either one is connected. So I disconnected both of them. I went ahead and drew power from the relay solenoid for my bypass but I screwed something up because I have to actuate the GPs before I switch on the ignition. I struggled for a while determining the problem because, while I could hear the relay working, and it was momentarily lighting my tester, I thought the controller was disrupting it immediately but what was actually happening was that the solenoid would make contact on the bounce but not remain engaged, even when powered up directly. But I'm still having way better luck with it now than I did. Ya'll have been very helpful on several of these threads. Thanks.