Glow Plug Relay

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Dec 23, 2007 | 03:49 PM

spunout

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Joined: Jan 2006

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Glow Plug Relay

I have noticed since the weather has starting getting colder that the mornings when it around 35 or below the truck has been had a harder time turning over like when your batteries are going. Last night it got down to about 25 and the truck was not plugged in. When I turned the key this morning nothing happened it didnt even try to turn over. So I turned off the key and back on and waited until the glow plug light went off and it turned over and started up with a little hesitation. I dont think its the batteries because when I first turned the key none of the dash lights dimmed like they usually would if the batteries were dead. Does this sound like a GPR? The truck is a 02 F250 4x4 PSD with 184K miles. I put in a new cps at 160K.

Dec 23, 2007 | 04:27 PM

greedy737

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Joined: Sep 2007

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From: Lenhartsville PA

Clean the batt. terminals and check the wires at the starter if they are tight.. If the batt's. are from new they will soon need replacement always replace both to!! I had to replace the usual things after 6 years, batt's., GPS, alt. starter!! Oh and CPS!!!!!!!!

Dec 23, 2007 | 04:31 PM

dryfly

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Joined: Jun 2007

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All you need to do is take a 12 volt test light.Connect it to the glow plug relay load side post.That is the side that goes to the glow plugs.And the glow plug relay is the one that is closest to the fire wall ontop of the motor,just behind the fuel bowl.If you turn the key to the on pos. and you get NO light then the relay is no good.If you do get a light it still doesnt mean that its in great shape.Apparently you gen get a pretty good voltage drop across a relay on the way out.Anyway if you find that it is bad I would then change it with a stancor relay.Much beefier.here is how to do it.http://guzzle.rbmicro.com/s_gpr.html .
You may want to bookmark guzzles homepage he is a wealth of info.Good luck.
Also the Wait to start light does not indicate weather or not the glow plugs are on .Its just an idiot light

Last edited by dryfly; Dec 23, 2007 at 04:33 PM.

Dec 23, 2007 | 04:32 PM

badger2196

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Joined: Mar 2005

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From: Larkspur, CO

All my winter starting issues were solved with new batteries and a new upgraded (Stancor) GPR (details here- http://guzzle.rbmicro.com/s_gpr.html)

Ooops - looks like dryfly beat me to it!

Dec 24, 2007 | 12:50 PM

spunout

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Ok i have not had a chance to hook up a volt meter but last night when u got home i plugged the truck in to see if that made a difference. I went out to start it this morning and it started right up. I guess what i wondering is a gpr thats bad or going bad cause problems one day and not the next or does plugging in the truck work as a band aid for a gpr that bad?