GLOW PLUGS WILL NOT TURN OFF!...HELP//

hEY GUYS,
My glow plug relay will not turn off. i have to manually unhook the 12v lower smaller wire (pink/w blk stripe) after i start the truck. because it gets 12volts when the Ing is on and after the truck starts it stays 12volts. wasted 8 glow plugs earler..i do not get the wait light at any time, cold or hot. I replaced my board with same results. checked the fuses, they are fine. maybe the inhibit switch ? Not sure where it is..or the engine temp switch? on passanger back of head stuck in the on position? Thanks!
Cevon/Kevin..

Oyes I bypassed the thing that lowers the voltage behind the engine. 28-12v. I ran a wire to the front battary. I was told I could have ran a wire to the small block next to the relay. Yes I will order a better relay when this is solved. Thanks again!..

It was a good idea running the wire to the front battery instead of the terminal next to it. Its a heavy load, and looks like you have a wire better suited for it.

When did your problem start? Would it by chance have been when you put the new solenoid/relay in?

It happened when I put 24V to the relay bypassing the thingy behind the engine that reduces the voltage. When I got the truck from the military someone borrowed it and I did not notice it missing and wired it wrong. after 12 starts the glow plugs burned out and i figured it out. Trying to put it back in shape..
Kevin./.

that relay in the pic looks new, have you replaced it already?

i would look at that first. if you pull the light blue wire off of the small terminal on the relay, do the glow plugs still come on? If they do then you have a relay that is grounding itself internally. if they dont come on you need to check that wire, it feeds directly to the glow plug controller under the dash for any place where it might have rubbed through the insulation and be grounding out.

I would suspect the relay is activating as soon as you turn on the key. This is probably due to what CC said, the relay is internally grounded. This is really easy to test with an ohmeter:

- unhook all wire from relay
-check each small terminal for continuity between itself and each of the large terminals, and ground

if you have continuity on any of these checks, you have the wrong relay.

Thanks, I just replaced the relay..Was told I cant use a ford relay. Need a heavy duty one. I will replace it with a OEM. I jumped the relay and it worked fine. Maybe its grounding like you said. On my M1008 the small pink small wire gives the relay 12vots when you turn the key on, when the wait light goes out it turns off the supply of 12v. M1008 does not do this, when the key is on 12v, after its running, still 12v...I can pull the card out, crank it and it makes no difference.. Key on, 12v, period. Guess I will go to a botton for the glow plugs after I check the blue wire for ground. I was hopeing a inline fuse somewhere was burned through. I checked my fuses in the fuse block, all ok..Something is not getting current to activate the board...Kevin...

Simple run down. Pink wire supplies 12v+ to the relay with key power. the other small wire blue? supplies 12v- from the controller card. If your relay is internally grounded, it will activate upon key power and stay that way.

You should be able to walk into a NAPA and tell them you need a totally isolated starter solenoid. (and actually I seem to recall the ford one is ok, if its pinned right)

Thanks.
I will check the relay to see if its grounded all the time.
Kevin...

Also check the connector on the temp switch at the rear of the engine on the driver's side. The GP card uses this to determine glow time. If it is disconnected, the card will think the temp is WAY too cold and, in my experience, will run the GP's for a LONG time. Too long for me to not turn the key off for fear of burning them up...

Just a thought....

I couldn’t tell from the photo in your other thread about the Glow card, but what batteries do you have in this truck???? They need to be a matched set (same age) and at least group 31.

I had a local customer who REFUSED to listen and use at least group 31 batteries (or 6TN) in his CUCV M1008. It ate at least 3 sets of glow plugs, burned out several starters, starter relays, Glow cards, and glow plug relays. He kept taking it to a local electrical shop, and ignored what I told him, which was to put in group 31 batteries (he had smaller cheaper Chicom mart jobs in it). He called me one day in disgust, after having the starter run on and the glow system fail again, and sold me the truck. I put in group 31 batteries, replaced the burned glow plugs, starter, and glow card. Never had any electrical problems with that M1008 for the next 2 years I owned it!!!!!

I think I got it!.

I installed the relay up side down, this reversed the small wires and also the large ones!.
I tested the relay and it is no good. I will order another for a cucv(hvy duty one) and install it correctly..!! When I took the small wires off the wait light started to work. reinstalled them correctly and everything worked except the ground on the relay is bad.
Thanks for your help, Will let you know how it turns out when i get back from vacation at Mertle beach..nc.
Kevin...

glad to hear you got it figured out.