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Ok everyone, back in trouble shooting mode. I just changed all my glow plugs cause a couple were bad, now I get no WTS light and no voltage to the plugs with the key turned. Is my conltroller bad (about 160 dollars at the cheapest!) how can I check to see if it is trully faulty?
A couple questions:
1. The signal and the timer for the wts light are in the solid state device under the magnestic controller yes??
2. Does anyone out there have a diagram of the wires to the controller? I saw Dave S's and that helped alot, but there are a couple extra wires that I didn't see in his photo.
Can anyone break down the exact operation of this system for me so I can get a better handle on solving this (times and voltages)
I have 12 volts comming in at the big yellow wires on one side of the controlller at all times. With the key turned I have 12 volts on the samller lead from the ignition to the controller .
Are there any other readings I can take to help nail down a casue or does this part just plain need replaced? Really don't wanna shellout all that coin>>
You do have power to controler and from igniton by your discription. On the controler there should be a wire going to a bolt (this is the ground). Clean this bolt and connection. I ran a separate wire from battery - side to this same bolt. this seemed to help a lot on my 93. If this doesn't work get back to me
if that doesnt work we'll do a control unit functional test..
1. with engine and igniton off connect a test light to terminal with metal strip hooked to it on top of the controler and run to a good ground. Have someone turn on ignition to run position. Light should stay on from 5-15 seconds in 35 degree weather. shorter time if warmer. I light doesn't come on or is on a very short time then unit has to be replaced. I found the local IH truck dealership had the best price for the controler. I've replaced mine 3 times. Once on a vacation towing a trailer.
Last edited by bigredtruckmi; Feb 25, 2006 at 06:36 PM.
check continuity from the glowplug wires back to the controler, if ok, then keep the glow plugs unpluged then take a jumper and jump the terminal with the white wire to ground, turn the igniton on, you should hear the relay click on, verify voltage at relay, at the terminal that has the metal jumper that goes to the controler, if you have 12v, the relay is good and the controller is bad, and no voltage is a bad relay
OK All.... I have been nukin this for a couple hours now. I jumped the white wire to ground with the key on... no click.. no thin... no voltage at the metal strip either. One thing that I did discover... (now that I have hung up my coveralls for the day) is that my small yellow wire is connected to the same terminal as the constants from the battery, when from what i am reading here lately it should be on the post that carries power to the glow plugs at the top of the metal strip. what is this yellow lead for and would it cause my misery here?...
the small yellow should be on the terminal withe the metal strip, jumping the white wire terminal to ground is what the controler does, it soulds like the relay is bad, has the controler always been wired like that? did it work in the past
Flkatbedjeff I just sent you a PM.
The yellow wire from the controller should be on the side of the relay with the metal strip.
The green wire from the controller should be on the terminal at the other end on the metal strip where the glow plug tan wires connect.
red wire from the controller goes to the ignition terminal on the relay.
White wire from the controller goes to the white wire terminal on the relay.
Black wire from the controller goes to ground. Check this one for a good ground.
Blue wire out of the controller goes to the wait to start light.
The green and yellow wires are part of what times the glow plug ON cycle.
It is possible the controller was toasted by having the yellow wire on the battery terminal.
Thanks all! I am gonna get it all straightened out tommorrow one way or the other (bypass or just replace the relay) I think I am pretty tight on everything here. This truck has a frsh rebuild in it and whoever did it hooked all the wires up wrong, I have been through a mile of these troubles so far (when I bought the truck I had all the dummy lights on and none of the gages worked.. now I am left with this Glow plug issue and all seems to be going great..... Hopefully I will get this ironed out tommorrow...