Glowplugs thinking out loud

[94turboidi]

Okay today while working on the truck the glowplug controller all of a sudden started smoking. I verified the wiring was correct a week or two ago and switched controllers from one I knew worked and it has been working fine. Well nothing has changed but now I can't hook up the glowplug main wire or it sparks. Its shorting out somewhere. I know thats what the glowplugs do is short out to create heat. Is that the only place it can ground to? These are motorcraft plugs.

I am considering wiring up a manual controller and trying to look around but if I do it I want to wire it all up from scratch to clean up this ancient wiring. They are 6 volt plugs right? They can't take 12 volt can they? If they could take 12 volts directly I was thinking that I could just use a starter solenoid and have a hot wire from the battery on one side and the other would go directly to all the glowplugs and the start wire would go to a push button. I dunno I am just thinking out loud. I would prefer to just simply fix my automatic setup. If I get a chance I will get a picture of it but its hooked up exactly like a pic I found on here, I think OLDBULL posted it showing which wire goes where. So maybe now that my motorcraft plugs are actually putting a good draw on the controller compared to the autolites something burnt out but what? I thought about buying a new relay or whole controller but wanted to get some ideas first.

 

[itsacrazyasian]

my truck has a push button setup with a glow plug relay but if you decide to ditch the whole thing with a push button, you can use a starter solenoid. i'm using zd9's. Was using stock 6.9 6v, went to 9v zd9. Had some cooler weather here in FL and my neighbor went to start the truck and said it fired right up with 8 seconds of glow time.

did you see if the solenoid is fried closed (constant power through both big lugs) or if its being grounded by the controller? My old 91 the controller went south and kept the glow plugs on till they burned out.

 

[94turboidi]

Yeah I got to thinking about it and I bet it is stuck open where they won't shutoff. Maybe I will just replace that relay. My trucks just in the xmas spirit right now. It just keeps on giving to itself.

 

[itsacrazyasian]

if the controller has gone jihad, its gonna keep the solenoid grounded. Grab a power probe or test light and see if the solenoid has power and ground on the little terminals. If you have constant 12v with key on and no ground but you have 12v on both larger lugs then you know you got a bum solenoid.

 

[94turboidi]

Well the key was off and it was still getting hotter. I can't hook up power to it or it starts sparking. I have the original gp controller that I might just put back on there to see if that works. I only switched because I got some of the wiring mixed up.

 

[itsacrazyasian]

Got a multimeter? Check for continunity between the two large lugs with the batteries disconnected. That will tell you if the relay is stuck closed. If theres no continutity, disconnect the glow plugs from the solenoid and hook the batteries back up and see if the controller is grounding the solenoid. Sometimes the solenoid might open back up but stick closed when a load is applied through it. Its happened a few times with a couple Ford starters. Same solenoid design, just its coil control side is a little different.

 

[OLDBULL8]

Which is getting hot, the controller or the solenoid?

If it's the solenoid, then it's arched and welded the contacts together. In that case you need a new solenoid. Disconnect the wire's going to the GP's, key on and see if it smokes.

If it's the controller, then something inside of it is shorted out, and it's fubared.

Had a controller on a truck that shorted out inside of it, smoked like crazy, burned up.

 

[94turboidi]

I'll have to mess with it some more I guess. I just took the battery cables off before any damage could happen. The scary part is thinking if I wouldn't have had the hood up and just shut the truck off and went inside. Makes me wish there was a breaker inline w/ the wiring. It seemed like it was coming from the solenoid, mainly where curvy metal pieces bolts onto the the solenoid. That was hot to the touch. I am debating just putting a new gp relay on, they are 18.00 but not in stock.

 

[itsacrazyasian]

just be careful of the aftermarket parts quality. I used to manage a few parts stores, i own a repair shop now. I wired in a led in the dash so i know if the glow plugs are still powered after i released the button and of course i can see if the lights dim.