HELP Won't Sart!!!!!

[IdahoPowerStroke]

Got down to 35 degrees this AM. First cold night of the Fall. "Wait Light" comes on like normal then goes off. Turn the key and the engine cranks but wont start. Just bought this in July and it has always started with no problems.

99 7.3

[colo86GN]

Check and see if your glow plug relay is working, that's what it was with mine. Also, batteries are really important on these.. not enough juice, it wont start.
Hope that helps!

[IdahoPowerStroke]

How do I test the relay?
12.25 volts at the batteries.

[colo86GN]

You can go out there with a volt tester.. check it with the key off and on, see if it is getting any power to it. Another way is you can see a slight difference in the volts when you turn the truck on.. i never noticed a difference in mine, but when i i put the new one in, i could hear it click on and the volts dropped a bit in the gauge. Before i changed mine it would only come on around the 5th time of cycling the key or hitting it with something.

[colo86GN]

Batteries sound good.. you need 10.5 volts for the truck to start. if its a 99-03 7.3 The glow plug relay will be the short relay located in the valley of the motor in front of the fuel filter housing.
Also, did you see any white smoke when you tried to start it? Have you tried any fuel additives at all? It's best to use an anti-gel in the winter or when it starts getting cold so you don't have any fuel problems.

[IdahoPowerStroke]

I located the GPR and with the key off I have 12v at the large lug with the boot protecting it. [first photo] When I turn the key on I get 12v at the large lug with the boot and at one of the small lugs. [second photo]

From what I know about relays when I turned the key on and power was applied to the small lug it should have energized the relay and sent power from the large lug that always has power to the other large lug which currently never has power.

If this is correct then this would mean the relay is not working. Am I correct???


Key Off


Only have power to these two lugs when the key is on.
Shouldn't the second large lug on the relay have power also when the key is turned on?

[IdahoPowerStroke]

Originally Posted by colo86GN

Batteries sound good.. you need 10.5 volts for the truck to start. if its a 99-03 7.3 The glow plug relay will be the short relay located in the valley of the motor in front of the fuel filter housing.
Also, did you see any white smoke when you tried to start it? Have you tried any fuel additives at all? It's best to use an anti-gel in the winter or when it starts getting cold so you don't have any fuel problems.

Yes it did emit white when it was trying to start. No additives is the fuel.

[colo86GN]

Additives are important at all times, but especially during the winter because the diesel fuel can gel. I usually use dieselkleen, you can pick it up at any parts store. The have a gray bottle and white bottle.. pretty sure the white one is the anti-gel, the other is for a summer use.
Also here is a thread on checking the glow plug relay to see whether or not it has power, But I think your right on!!
Glow Plug Relay Question