glow plug relay

nocturnal_racing · #1 (**permalink**) 02-24-2012, 02:52 AM

Hello all new here! I am pretty mechanical but when it comes to deisel diagnosting I am lost. I own a 96' F350 7.3 4x4 4 door. When I got the tuck it had a utility box on it and I was averaging 18 mpg. Over time i switched the bed out for a regular bed. Now over time I am down to about 12 mpg now. I came to the conclusion that the map sensor was bad do to power loss. I replaced it and my power is back. I also replaced ebs tube. ( Now shifting better) I noticed the other day when I changed my fuel filter that the fuel heater is disconnected and obviously broke. Will this have anything to do with fuel milage? Also I know my glow plugs are not working, but I keep the truck plugged in when temps are below 55 degrees. Also was wondering if anyone has ever used starter solenoid to replace the glowplug relay. Seems like same set up and 15 bucks cheaper. Any suggestions or help would be appriciated.

Thanks Dave

**Fordman247365** · #2 (**permalink**) 02-24-2012, 05:22 AM

It will work but it wont last, a starter solenoid is made to cycle for 15 sec or less and GP's cycle for up to 2 minutes, the starter one probably wouldnt last a week. If you want just about the best GPR there is, get a stancor relay, it is heavy duty and can handle the demand of the glow plug system and lasts way longer than a standard GPR

586-902 Stancor General Purpose / Industrial Relays

**baderic03** · #3 (**permalink**) 02-24-2012, 06:18 AM

as far as fuel bowl heater goes dont worry about it as far as glow plug relays go but either a replacement or one for a winch that is 100% duty cycle or a stancore

nocturnal_racing · #4 (**permalink**) 02-24-2012, 10:00 AM

ok ty is there anything other than the relay on there that looks like the solenoid.

nocturnal_racing · #5 (**permalink**) 02-24-2012, 10:08 AM

I saw in front of the fuel filter area. there is a harness with a square fuse looking thing any idea what that is.

Patrick Feeley · #6 (**permalink**) 02-24-2012, 11:42 AM

The square thing is probably the Water-In-Fuel (WIF) switch which is a little solid-state device. On the starter relay for a GPR question: You need to make sure that whatever relay you try is NOT CASE-GROUNDED (it must be case-isolated like the factory ones), otherwise the glowplugs will not turn off. Go with the Stancor. If you need to go cheap, get a Sorensen MR99 from AutoZone or a GPR-109 from NAPA (and order them by the part number, not by application because they will try to sell you something else). Both will work, but don't count on them to last. Cheers!

Hendricksbus · #7 (**permalink**) 02-24-2012, 11:55 AM

i just put in a cat relay and i'm loving the fast starts now....

nocturnal_racing · #8 (**permalink**) 02-24-2012, 12:42 PM

Quote:

Originally Posted by Patrick Feeley

The square thing is probably the Water-In-Fuel (WIF) switch which is a little solid-state device. On the starter relay for a GPR question: You need to make sure that whatever relay you try is NOT CASE-GROUNDED (it must be case-isolated like the factory ones), otherwise the glowplugs will not turn off. Go with the Stancor. If you need to go cheap, get a Sorensen MR99 from AutoZone or a GPR-109 from NAPA (and order them by the part number, not by application because they will try to sell you something else). Both will work, but don't count on them to last. Cheers!

this looks like a fuse one of those goofy breaker ones square with two wires going to it. it is black, not on glowplug relay, clear top on it. Sits lose up near the eps. no one seems to know what it is. I will have to take picture of it.