need some GP / GPR help
Thread Starter
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Mountain Pass
Joined: Jun 2010
Posts: 205
Likes: 3
need some GP / GPR help
Ok guys, I need alot of help 
. I have read the threads on the glow plugs and its all starting to run together. If you don't mind see if i am on the right track. On a 99 psd I am guessing the gpr is next to the fuel filter and I need to see if both large post and both small post are hot when the key is first turned on and the motor is cold. If I am not getting around 12v on all 4 post, then the GPR is bad. If all is hot, disconnect the harness going to the valve cover and test the 4 outside pins on the harness for .8 to 1.5 ohms. If i get out side that, start pulling valve covers and gp's?
Any help would be great and as always,
Thanks,
Levi
. I have read the threads on the glow plugs and its all starting to run together. If you don't mind see if i am on the right track. On a 99 psd I am guessing the gpr is next to the fuel filter and I need to see if both large post and both small post are hot when the key is first turned on and the motor is cold. If I am not getting around 12v on all 4 post, then the GPR is bad. If all is hot, disconnect the harness going to the valve cover and test the 4 outside pins on the harness for .8 to 1.5 ohms. If i get out side that, start pulling valve covers and gp's? Any help would be great and as always,
Thanks,
Levi
Elder User
Joined: Oct 2007
Posts: 935
Likes: 1
From: Bowling Green, KY
There are two relays behind the fuel filter. The one closest to the firewall is the GPR. You should always have 12v+ to the large post to the left if looking at the front of the truck. When you turn the key on you should see 12v+ to the large post on the right. If you do then ohm the glowplugs. If you dont have 12v to the right post then the GPR is shot
Post Fiend
Joined: Nov 2007
Posts: 9,549
Likes: 14
From: Payson, AZ
To really check the control leads, small wires, they need to be disconnected because one supplies battery and the other ground.
Check the large terminals and if they test OK the control leads are fine.
You will see a drop in voltage on both large terminals with key on and the GPR operates. That means the GPs are drawing current to heat up.
Check the large terminals and if they test OK the control leads are fine.
You will see a drop in voltage on both large terminals with key on and the GPR operates. That means the GPs are drawing current to heat up.
Thread Starter
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Mountain Pass
Joined: Jun 2010
Posts: 205
Likes: 3
Thanks for the help guys, I drove home for lunch (4 miles) and let it sit while i ate, I went out and tested the GPR to discover with the the following using the handy pic
Key off:
2 - 12v
3,4,5 - no volts
Key on not running:
2,3 - 12v
4,5 - no volts
I am going to make a wild assumption here and say the GPR is trash? My second thought is why is the truck smoking with a strong diesel smell when only cycling the key numerous times if the GPR is bad?
thanks again
Key off:
2 - 12v
3,4,5 - no volts
Key on not running:
2,3 - 12v
4,5 - no volts
I am going to make a wild assumption here and say the GPR is trash? My second thought is why is the truck smoking with a strong diesel smell when only cycling the key numerous times if the GPR is bad?
thanks again
Posting Guru
Joined: Feb 2010
Posts: 1,411
Likes: 1
From: Opelika, AL
Trending Topics
Elder User
Joined: Oct 2007
Posts: 935
Likes: 1
From: Bowling Green, KY
If the truck was still cold then the GPR is trash. I would recommend that you replace with this:
Welcome to guzzle's Stancor GPR replacement Mod Web Page
Mine stars alot better after the GPR replacement
Welcome to guzzle's Stancor GPR replacement Mod Web Page
Mine stars alot better after the GPR replacement
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Laughing Gas
Joined: Feb 2007
Posts: 775
Likes: 0
From: Williamston, MI
Keep in mind that the GPR could measure voltage on #4 above but not have enough juice to the plugs to fully operate them. Also, I have had on GPR that would power some times and not others. I did the Stancor too. No more problems... with GPR anyway
Thread Starter
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Mountain Pass
Joined: Jun 2010
Posts: 205
Likes: 3
just for grins, i went out a second ago and double checked myself and i only have 1 relay on top of the motor. it is brown and looks like the one in the pic that was posted is this the correct relay or is it the one bolted to the pass front fender with the two big post tied together with a double eye battery cable?
Thread Starter
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Mountain Pass
Joined: Jun 2010
Posts: 205
Likes: 3
Its not a CA truck, I know the guy that bought the truck new and when he traded it i bought it, she (the truck) always lived in Texas. so i am stumped yet again on what the heck to do. please keep the post comin and i'll keep a checkin.
thanks,
Levi
thanks,
Levi
Thread Starter
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Mountain Pass
Joined: Jun 2010
Posts: 205
Likes: 3
there is only one....what is the AIH and what does it hurt being gone?