Odd glow plug issue.
Laughing Gas
Joined: Oct 2009
Posts: 882
Likes: 11
From: Eastern CT
I'm tempted to say that you have an issue with your GPR. I would only recommend a Stancor or Western plow relay for your GPR. These trucks use a lot of power for the glow plugs. When was the last time you checked the wiring harness for the glow plugs? Have you used a meter on your GPR when the key is on to see what is going on with it?
Red
Red
Laughing Gas
Joined: Oct 2009
Posts: 882
Likes: 11
From: Eastern CT
For the GPR, I would recommend using a meter so you can see how much voltage drop you have across the terminals. A test light is only going to show you that you have enough power to light a little light bulb.
Red
Red
Lead Driver
Joined: Apr 2016
Posts: 7,177
Likes: 1,335
From: Bahstun
if you tighten the GPR posts too tight, you will twist the contacts and it might not work well after.
Same happens on fender starter solenoid on fords. they are copper and don't hold up well to strong torque
Same happens on fender starter solenoid on fords. they are copper and don't hold up well to strong torque
Postmaster
Joined: Sep 2007
Posts: 4,195
Likes: 6
From: Medford Oregon
On the GPR one little terminal with key ON will show battery voltage all the time. The other little terminal is pulled to ground by the PCM to activate the GPR. Since it's intermittent I would check the connections on those two small terminals.
Some Other Troubleshooting:
Disconnect both small wires. Measure each with key ON. The one that has battery voltage comes from the ignition switch. Connect that wire back up to the GPR. Use a jumper wire on the other GPR small terminal and ground it to battery negative. Each time you do this the relay should energize. Removing the ground and the GPR will De-energize. You can do this as may times as you like with key ON to prove to yourself the GPR is operational.
It almost sounds like one of the small terminal wires at the connector to the GPR is bad - intermittent. Close inspection should revel that. A picture would help.
Some Other Troubleshooting:
Disconnect both small wires. Measure each with key ON. The one that has battery voltage comes from the ignition switch. Connect that wire back up to the GPR. Use a jumper wire on the other GPR small terminal and ground it to battery negative. Each time you do this the relay should energize. Removing the ground and the GPR will De-energize. You can do this as may times as you like with key ON to prove to yourself the GPR is operational.
It almost sounds like one of the small terminal wires at the connector to the GPR is bad - intermittent. Close inspection should revel that. A picture would help.
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Laughing Gas
Joined: Sep 2007
Posts: 869
Likes: 5
From: Near Shenandoah Valley
Sorry I was so long getting back. On Saturday morn, while laptop was charging up the truck had been started 3-4 hours earlier and ran 15 minutes. When cycling key on/off the DVM read less than one (1) volt on load side terminal of GPR. Air temp 22*.
This morning, similar temps, truck was plugged up maybe 2 hours. A/E read oil temp 64* and coolant temp read 145* ???? After running about 15 minutes the dash gauge was below normal operating temp but the A/E live feed was reading 302* and outlined in red.
I picked up a new coolant temp sending unit and GPR and will try to replace tomorrow.
This morning, similar temps, truck was plugged up maybe 2 hours. A/E read oil temp 64* and coolant temp read 145* ???? After running about 15 minutes the dash gauge was below normal operating temp but the A/E live feed was reading 302* and outlined in red.
I picked up a new coolant temp sending unit and GPR and will try to replace tomorrow.
Post Fiend
Joined: Dec 2010
Posts: 10,121
Likes: 3
From: Orrville, Ohio
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Laughing Gas
Joined: Sep 2007
Posts: 869
Likes: 5
From: Near Shenandoah Valley
You (me at least) would expect a new, out of the box GPR to last more than a few starts. New GPR, 12.6 on line side, 12.2 on load side. Truck started like a youngster again.
I would like to thank each of you for putting up with someone whose meds were off (and their GPR) but now fixed.
Check the simple stuff first.
I would like to thank each of you for putting up with someone whose meds were off (and their GPR) but now fixed.
Check the simple stuff first.
Logistics Pro
Joined: Mar 2007
Posts: 4,575
Likes: 836
From: knoxville, tn
Sadly, New does not equal good for GPRs.
I would recommend:
Monster White-Rodgers Glow Plug Relay
It will handle the high amp draw with no problem.
I would recommend:
Monster White-Rodgers Glow Plug Relay
It will handle the high amp draw with no problem.
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