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Plowhand, after reading some about the gpr switch I am confused because you wrote to me time ago:
RÖENTGEEP, to do the glow plug switch, locate the glow plug relay (looks like the starter relay thats on the fender) on the front right (passengers side) of the engine, under the cover. There will be two big wires and two small wires, disconnect the two small wires or unplug them if yours has the plug. With a volt meter or test light, find the one that has power when the key switch is turned on. Cut this wire,add enough wire to go inside the cab to the dash, attach a switch, run wire back to the other end of the cut wire and attach. Re-connect the two small wires to the relay. Your "Wait to Start" light will still come on, but your glow plugs will not have any power unless you flip the switch.
And later to Yokounsly : So one of the easiest fixes for your problem that I have done before is: turn your key on and check to see if you have power on one of the small wires to the GPR. The other small wire should show a ground, if it does not then the PCM is not completing the circuit. Take this wire, cut it, splice into it (I would run two sizes bigger "lower #") and run it to a switch (that you mount in your dash) then to a small 12 volt LED light (color of your choice) then to a good ground. The switch could be a momentary one if you want to hold it in until you start or a regular one (the regular one will keep your glow plugs on until you turn it off, so don't forget to turn it off). Hope this helps.
The questions is cut the hot wire or the ground wire?
RÖENTGEEP, both of them work, but the first way, the one that I told you, lets the PCM turn off the glow plugs if you leave them on. If I remember correctly in talking with you then that was what you were looking for.
The second way, the one that I told yukonsly, you have total control over the glow plugs and as long as the switch is on the glow plugs are activated. If you leave the switch on for two hours the glow plugs are on for two hours.
This is an old post but I'm getting ready to do this mod. How many amps should the switch be rated at? I'm thinking not very many as it's on the primary side of the relay.
Thanks guys. I'm hoping to get my CCV mod, GPR switch and rear air bags on before a wheeling trip to Utah in early Oct when I'll be hauling toys again.
seems to me, positive or ground, all u are doing is interuppting the circuit to disable the gplugs. with the switch in the on position, everything should act normal. this would only apply to overidding the glowplugs not fixing a problem.