My First Time :
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My First Time :
Lot of info here. Been reading board before I had problem -- I have a 1996 F-350 7.3 Turbo Diesel. Several mornings ago started - blowing white smoke - would not start until I charged batteries - all the way up - to 12.8 - would not start if batteries tested at -- 12.5. I put two new batteries in - still have same problem -- changed GPR -- still won't start Could someone tell me the VOLT readings I should get off the terminals at the GPR?
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If you get a minute check out the link here, it will help you to navigate around and understand this site.
https://www.ford-trucks.com/forums/s...d.php?t=300691
We are happy you have chosen the best source for Fords!
Enjoy FTE and The State Chapters are located at the bottom of the main forum page.
JOIN CLUB FTE -SUPPORT THE FORUMS!
See you on the boards.
….
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Joined: Jul 2005
Posts: 261
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From: North Carolina
Welcome to FTE.
I copied this out of the first thread in this forum, "Official Glow Plug/gpr...." Alot of good info in it. Here's the part I copied for you:
Glow Plug Relay Test Procedure:
I copied this out of a post from the link below:
https://www.ford-trucks.com/forums/s...d.php?t=426789
I have attached a small photo of the glow plug relay, as seen from looking from the front of the truck. (Click on link above to see picture)
The large terminal on the left with a rubber boot over it goes directly to the batteries. It has +12 volts all the time.
The other large terminal, without a boot, is the switched +12 volts that is fed to the glow plugs when they are supposed to be on. That current gets fed to the glow plugs through the brown and yellow wires (below). I don't know where the blue wire goes. Anybody got those factory wiring diagrams?
The smaller terminal at the bottom has no voltage when the key is off, but gets +12 volts any time the key is on, engine running or not. It is the incoming current supply for the relay's coil.
The other smaller terminal, closer to the firewall, is the other side of the relay's coil. It is looking for a ground to activate the relay. When the key is first turned on, and glow plug heat is called for by the PCM (the engine computer), the PCM outputs a ground, thereby causing current to flow through the relay's coil, activating the relay, and sending current (at +12 volts) to the glow plugs. When glow plug heat is no longer called for, the ground that is output by the PCM goes "open", causing the relay to turn off. If you put a volt meter on this pin after the relay opens, you will see +12 volts here, too. Why? The wire in the relay's coil is feeding it to your volt meter.
If you short this terminal to ground through a switch, you can manually control the current to the glow plugs any time the key is on.
Since the winter weather is usually not that cold here in Southern California, I intend to install a switch inside the cab that opens the connection to this terminal. That will allow the timer to control the glow plugs normally ONLY when I want it to. Otherwise, when I don't need the glow plugs to be heated, I'll save myself the current drain on the batteries.
You could also wire a momentary-contact push button switch in the cab and have glow plugs only when you push the button, and complete manual control if you want it. I wouldn't use a toggle switch, as it could be forgotten and the glow plugs would be on all the time. Not a good thing.
I copied this out of the first thread in this forum, "Official Glow Plug/gpr...." Alot of good info in it. Here's the part I copied for you:
Glow Plug Relay Test Procedure:
I copied this out of a post from the link below:
https://www.ford-trucks.com/forums/s...d.php?t=426789
I have attached a small photo of the glow plug relay, as seen from looking from the front of the truck. (Click on link above to see picture)
The large terminal on the left with a rubber boot over it goes directly to the batteries. It has +12 volts all the time.
The other large terminal, without a boot, is the switched +12 volts that is fed to the glow plugs when they are supposed to be on. That current gets fed to the glow plugs through the brown and yellow wires (below). I don't know where the blue wire goes. Anybody got those factory wiring diagrams?
The smaller terminal at the bottom has no voltage when the key is off, but gets +12 volts any time the key is on, engine running or not. It is the incoming current supply for the relay's coil.
The other smaller terminal, closer to the firewall, is the other side of the relay's coil. It is looking for a ground to activate the relay. When the key is first turned on, and glow plug heat is called for by the PCM (the engine computer), the PCM outputs a ground, thereby causing current to flow through the relay's coil, activating the relay, and sending current (at +12 volts) to the glow plugs. When glow plug heat is no longer called for, the ground that is output by the PCM goes "open", causing the relay to turn off. If you put a volt meter on this pin after the relay opens, you will see +12 volts here, too. Why? The wire in the relay's coil is feeding it to your volt meter.
If you short this terminal to ground through a switch, you can manually control the current to the glow plugs any time the key is on.
Since the winter weather is usually not that cold here in Southern California, I intend to install a switch inside the cab that opens the connection to this terminal. That will allow the timer to control the glow plugs normally ONLY when I want it to. Otherwise, when I don't need the glow plugs to be heated, I'll save myself the current drain on the batteries.
You could also wire a momentary-contact push button switch in the cab and have glow plugs only when you push the button, and complete manual control if you want it. I wouldn't use a toggle switch, as it could be forgotten and the glow plugs would be on all the time. Not a good thing.
