GP Control switch
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From: Inland Empire, So Cal
GP Control switch
I have been having problems with starting my truck and a buddy of mine looked and my chiltons and thinks that my problem may be my Glow Plug Contol Switch. I guess it threads into the "left cylinder head coolant jacket" Has anyone ever had to replace this swicth and does anyone know part #'s? Thanks a bunch
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From: Silver Lake Dunes, MI
Nope it doesn't exist! Chiltons might be for an IDI. The Glowplugs are controlled by the PCM and refer to the oil temp, barometric pressure and I think the Intake air temp to calculate GP on time.
Check the relay with key on for power on both larger lugs. this is best with two people so you don't have to wonder if the relay already turned off. If you don't have power on both and the relay clicks you need a new relay. if you have power on just one and no click you either need a relay or there is a control side problem. The PCM controls the ground side of control circuit. so one of the small terminals should have a constant 12 volts with the key on.
Check the relay with key on for power on both larger lugs. this is best with two people so you don't have to wonder if the relay already turned off. If you don't have power on both and the relay clicks you need a new relay. if you have power on just one and no click you either need a relay or there is a control side problem. The PCM controls the ground side of control circuit. so one of the small terminals should have a constant 12 volts with the key on.
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I've already changed out the GP relay 3 times since the problem started a couple months ago and it melted out one of the large posts on one and has been having hard/no start for what seesm like forever...
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Originally Posted by tjbeggs
Time to check the ohm readings on the GP. Also could be shorted to ground. Might need to pull the valve covers and make sure none of the wires are rubber a push rod.
Post Fiend
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From: Silver Lake Dunes, MI
Seems like it would be right then. I would check for power on both large terminals again just to make sure its energizing.
I just noticed you live in SoCal. is your truck a cali emissions?
I just noticed you live in SoCal. is your truck a cali emissions?
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Post Fiend
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From: Silver Lake Dunes, MI
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