Need Help-Got a 89-F250 with 7.3 IDI-The WTS light will come on when key is turned on,but will go off in about a second and relay will click until cycle is stopped-I have put a new glow plug controller on and have tested each glow plug and they test good with test light-Had a diesel guy look at it and said I am not getting power to my glow plug controller-This all started about a week ago after I installed a new cord for my engine block heater-I don’t know if that makes any difference,but had no issues before new cord was put on-Now it will only crank if it is plugged up.Any suggestions would be greatly appreciated.Thanks!
89-F250
- Thread starter Blueridge
- Start date
if there not motorcraft GPs then i would be taking them out good or not.
the off brand GPs can cause short cycle problems with the controller. i had that happen to me before i knew better to only use motorcraft parts.
the off brand GPs can cause short cycle problems with the controller. i had that happen to me before i knew better to only use motorcraft parts.
If the mechanic said you are not getting good power to the controller, do what one of the previous posters mentioned and follow the wires on top of the engine over to the pass side, and when you get in front of the A/C box a little bit beyond the pass side valve cover, look for a big wiring plug. You should have two fat yellow wires going through that plug, the plug is probably melted like he mentioned. You can cut the yellow wires and run them around the melted plug. They are what supply the power to the gp controller.
icanfixall
Official GMM hand model
Welcome to the forum. Knowing what brand of glow plugs is very important. so please find out what you have. Next please know this forum has extensive work on what plugs work. That is Motorcraft Beru ZD9 plugs. Nothing else will give good long service.
Now listening to a thought that the controller is not getting power please look at the engine main wiring harness plug that is located on the passenger side of the engine. Just find the bundle of wires that feeds all the accessory on the engine.The harness plug is about 1 inch wide and 3 inches long. On one end of this plug you have 2 yellow wires that feeds power from the passenger side fender mounted solenoid to the controller. This wire has both yellow wires in the same lug on both ends. This wire is ALWAYS hot and has power on it all the time. Be careful. Our engines have several other hot all the time wires.. In that harness plug when you open it you probably will see dirt or some melting. Many have simply just bypassed this plug with the glow plug controller so do not worry is you find melting. Its normal but a horrible poor design.. Post back what you find.n
Now listening to a thought that the controller is not getting power please look at the engine main wiring harness plug that is located on the passenger side of the engine. Just find the bundle of wires that feeds all the accessory on the engine.The harness plug is about 1 inch wide and 3 inches long. On one end of this plug you have 2 yellow wires that feeds power from the passenger side fender mounted solenoid to the controller. This wire has both yellow wires in the same lug on both ends. This wire is ALWAYS hot and has power on it all the time. Be careful. Our engines have several other hot all the time wires.. In that harness plug when you open it you probably will see dirt or some melting. Many have simply just bypassed this plug with the glow plug controller so do not worry is you find melting. Its normal but a horrible poor design.. Post back what you find.n
Ok thanks so far-Last year I had found that the harness that you all are describing was indeed melted so I have bypassed it with the yellow wires-I’m 95% sure the plugs are the dreaded Autolite-I am now at my in laws shop waiting on the part store to bring some motorcraft plugs-Im going to change them out and see if this works.Thanks again!
Ok guys thanks for all your help-just installed new motorcraft plugs and light came on and cycled correctly and truck fired right up-Thanks again!
Also-I noticed my glow plug connectors are a little sketchy and saw a new harness is outrageous-Does anybody have any thing good you are using for connectors?
Also-I noticed my glow plug connectors are a little sketchy and saw a new harness is outrageous-Does anybody have any thing good you are using for connectors?
79jasper
Chickenhawk
Blue female bullet connectors.
Sent from my SM-G892A using Tapatalk
Sent from my SM-G892A using Tapatalk
That's whats wrong with mine. I could fiddle with the plug connectors and it would cycle normally for about a week or two, and then it would flake out again. Mess with the glowplug connectors and it would be ok again for another week or so.
After that I went to the dark side and just put a manual button on my controller. No more problems. Everything has to be exactly right, or the automatic portion of the controller will throw a fit and short cycle the plugs.
icanfixall
Official GMM hand model
Not to worry if the harness plugs have the insulation broken off at the plug. As long as the harness is plugged in tight to the glow plug you wont have any issues with it grounding to the heads or block. Might need to pinch the ends with a pair of pliers to make a tighter connection. Glad you got rid of the Autolites too and installed the best..Motorcraft Beru ZD9 plugs.
