M1008 Glow Plug Issue

[Jersey4x4]

OK A few weeks ago my wait light went on at cold start but no relay click and no preheat so I jumpered the relay under the hood and it has been fine ever since then until tuesday when I did some 4wheeling in deep water and ever since then the glow plugs do not operate. I have a wait light but now relay click or battery drain, I jumper the relay until wait goes out then starts right up. I followed the TM 9-2320-289-20 and ran all tests and all are OK except the yellow wire at 800 Ohms when cold...What defins cold when it is 90deg out side. And also the pink/black & light blue wires on glow plug relay readings were low at 2.5 when says 6-10 so it says replace the relay. OK where to get the relay. I used the NSN number from 289-20P but cant get anywhere. What relay to use? I just bought a new controler and that did not help so it must be glow plug switch on passenger side rear head or the relay on firewall. now the relay does energise during diagnostic of light blue wire so I guess it is OK so that leads me to the glow switch. Any other tips that would help would be greatly appreciated. Thanks

Also I have some Misc CUCV parts listed on eBay at www.stores.ebay.com/Jersey-Shore-4x4

 

[CCATLETT1984]

you can get the relay at any parts store. I dont have the # with me, but give it a day or two and someone will post it.you can jumper the coolant switch that you think is giving you issues, it will just cycle the glow plugs at every start (including when the engine is hot) If they operate with that switch jumped, then you can just replace it (std. civilian part is the same)

 

[Jersey4x4]

Re: RE: M1008 Glow Plug Issue

you can get the relay at any parts store. I dont have the # with me, but give it a day or two and someone will post it.you can jumper the coolant switch that you think is giving you issues, it will just cycle the glow plugs at every start (including when the engine is hot) If they operate with that switch jumped, then you can just replace it (std. civilian part is the same)

I thought it was standard relay until I checked the part numbers from the 20P and 34P manuals and the number does not cross to anything and it is not available. Does anyone have the number they can give me so I can solve this. Is there just one relay for the glow plugs? I thought there was one inside under the dash also but nothing in the manual shows another relay, just the starting relay behind where the radio would be. This sucks every morning to start the truck.

 

[mangus580]

RE: Re: RE: M1008 Glow Plug Issue

The relay you are looking for is on the firewall just left of the Master Cylinder. It is a silver can with 4 terminals on it. 2 large, 2 small. Go to napa, tell them you need a 'solenoid' with all isolated terminals. If they look at you funny, tell them that the 2 small terminals can not connect to ground OR either of the positive posts.

You may find if you go ask for a mid-80s glow plug relay for a Ford....

 

[Jersey4x4]

Re: RE: Re: RE: M1008 Glow Plug Issue

The relay you are looking for is on the firewall just left of the Master Cylinder. It is a silver can with 4 terminals on it. 2 large, 2 small. Go to napa, tell them you need a 'solenoid' with all isolated terminals. If they look at you funny, tell them that the 2 small terminals can not connect to ground OR either of the positive posts.

You may find if you go ask for a mid-80s glow plug relay for a Ford....

I came up with part numbers of 98226 & the GM number 14076885 but they dont exist. I tried to get an isolated solonoid from NAPA but all of them have only 1 small terminal and when we looked through the picture book all of the 4 terminal units were discontinued.

Do you think this relay is my problem before I go through all of this to find one?

 

[mangus580]

RE: Re: RE: Re: RE: M1008 Glow Plug Issue

How are you jumping the relay?

 

[Bigmick]

I don't know if it's the exact same one, but LMC Trucks sell a glow plug relay for 6.2 Blazers, it says this in their online catalogue,

RELAY-GLOW PLUG In Stock $21.95

Mick.

 

[acetomatoco]

As it is a standard 12 V relay, you can get as many as you want at NAPA or other nice place like that... The large terminals do not know what voltage they are getting ... just amperes...and they work fine... Make sure you get a metal can and not the plastic one which was discontinued.

 

[Jersey4x4]

Re: RE: Re: RE: Re: RE: M1008 Glow Plug Issue

How are you jumping the relay?

with the key off I am jumping from the power on the relay(red wire to the small terminal on the highest point or the relay(blue I think) now if I unplug the pink wire on the IP it does not jump and if the key is on it will blow the 20amp ignition fuse.

 

[mangus580]

RE: Re: RE: Re: RE: Re: RE: M1008 Glow Plug Issue

It almost sounds like something is wired wrong. Can you get me a good picture of your relay so I can see how its hooked up?

 

[Jersey4x4]

Re: RE: Re: RE: Re: RE: Re: RE: M1008 Glow Plug Issue

It almost sounds like something is wired wrong. Can you get me a good picture of your relay so I can see how its hooked up?

I sure can, I will do it today.
The thing is that it was working fine with no problems since I have owned the truck. I have had the M1008 for almost a year with no major problems until this. It was government owned before that so the wiring should not have been changed. I will get a pic in a little while.

 

[CCATLETT1984]

Re: RE: Re: RE: Re: RE: M1008 Glow Plug Issue

How are you jumping the relay?

with the key off I am jumping from the power on the relay(red wire to the small terminal on the highest point or the relay(blue I think) now if I unplug the pink wire on the IP it does not jump and if the key is on it will blow the 20amp ignition fuse.

to jump the relay you should be touching a ground to the same small terminal that the blue wire is attached to.

 

[Jersey4x4]

Re: RE: Re: RE: Re: RE: M1008 Glow Plug Issue

How are you jumping the relay?

with the key off I am jumping from the power on the relay(red wire to the small terminal on the highest point or the relay(blue I think) now if I unplug the pink wire on the IP it does not jump and if the key is on it will blow the 20amp ignition fuse.

to jump the relay you should be touching a ground to the same small terminal that the blue wire is attached to.

OK I have not gotten pictures yet but will do tomorrow. I grounded the blue wire terminal today and nothing but when the key was on it cycled the relay and the glow plugs worked. I am guessing by this and all other tests that the relay is good. When I put 12v to the blue wire with the key off there is a relay in the cab tinging? I am sure it is the start relay. Could this relay cause my no glow plug issue? I still get the wait light every morning but no glow plug relay click and no start until I jump out the relay. Is ther a test procedure for the glow plug control card? I cant seem to find one anywhere in the Tech Manuals.

 

[CCATLETT1984]

RE: Re: RE: Re: RE: Re: RE: M1008 Glow Plug Issue

that light blue wire is a ground (DON'T RUN a POSITIVE TO IT), the relay is switched by completing the ground circuit. the glow plug controller card does that. that relay should click when you ground the terminal that the light blue wire is connected to. do you have 12v at the other small terminal with the key off? key on?
if its not getting voltage to that small terminal then it cant activate the relay when the ground is switched.

in reality the wait light has nothing to due with the relay operation, it only goes by the gp, inhibit switch in the head to decide whether or not to glow the plugs. I have my truck setup to use a manual button to glow the plugs, but left the card in so the wait light still comes on, i just hold the button till the light goes out.

 

[Jersey4x4]

Re: RE: Re: RE: Re: RE: Re: RE: M1008 Glow Plug Issue

that light blue wire is a ground (DON'T RUN a POSITIVE TO IT), the relay is switched by completing the ground circuit. the glow plug controller card does that. that relay should click when you ground the terminal that the light blue wire is connected to. do you have 12v at the other small terminal with the key off? key on?
if its not getting voltage to that small terminal then it cant activate the relay when the ground is switched.

in reality the wait light has nothing to due with the relay operation, it only goes by the gp, inhibit switch in the head to decide whether or not to glow the plugs. I have my truck setup to use a manual button to glow the plugs, but left the card in so the wait light still comes on, i just hold the button till the light goes out.

Yes the other terminal has power tested by test light. I did not use a volt meter to check voltage though. If all this is good what else is there to test or go bad?

 

[Jersey4x4]

RE: Re: RE: Re: RE: Re: RE: Re: RE: M1008 Glow Plug Issue

can the control card be tested?

 

[ida34]

RE: Re: RE: Re: RE: Re: RE: Re: RE: M1008 Glow Plug Issue

The -20 or the -34 manual has a pin by pin check of the inputs for the card. If all the inputs are up to speed then the card is bad. No real test of the card just testing all the inputs to the card.

 

[Jersey4x4]

Re: RE: Re: RE: Re: RE: Re: RE: Re: RE: M1008 Glow Plug Issu

The -20 or the -34 manual has a pin by pin check of the inputs for the card. If all the inputs are up to speed then the card is bad. No real test of the card just testing all the inputs to the card.

If all thoes checks are ok which they are then the card is FUBAR

Where can I get one, New preferably or used if I have to?

 

[CCATLETT1984]

RE: Re: RE: Re: RE: Re: RE: Re: RE: Re: RE: M1008 Glow Plug

if its the card, just hook up a manual switch and operate the plugs by hand, you can leave the card hooked up so your wait light will still function.

 

[Jersey4x4]

Re: RE: Re: RE: Re: RE: Re: RE: Re: RE: Re: RE: M1008 Glow P

if its the card, just hook up a manual switch and operate the plugs by hand, you can leave the card hooked up so your wait light will still function.

I have it jumped that way now but would rather fix it corectly. I may just disect the card and see what is bad and repair it. Or hop the fence at the 119th and grab one of theirs. Shhhhhhh I did not say that.