M1008,,what a trooper! Starting at 16 deg...

[Milbikes]

What a truck! It started today at 16 degrees. Granted, it took a little cranking, but it started. I had to take it in to work because the 6.5 Suburban wouldn't start.

I checked the glow plugs in the M1008 with a meeter tonight, and I quit after I found 4 with no resistance. And still the old beast started! Tomorrow after work I want to replace the glow plugs with AC 60G plugs. I want to do that mod I have seen mentioned that will prevent my glow plugs from 'daisy-chaining' out if one goes bad. My brain and body are too tired to search for the best description of the mod. Maybe Santa will reply?

The more I drive this truck, the more I like it. I am getting used to 50mph again. H.

 

[Milbikes]

I found a description of the mod (24 volts glow plug feed swap to 12volt feed) but a picture would really help. H.

 

[Westech]

why would you want to change the feed to the glow plugs? I have a feeling you do not understand how the system works. The soick feed wire comes from the 24V side and passes in to a resestor that drops it to 12V..... they did this so that both batteries supply the power and it will not drain the first battery and would have more supply amps when needed. unless the resestor is missing or burned out (then it would supply no power) just leave it alone and replace the glow plug with 12V units NOT hummer 24V.

 

[Sasquatch]

I know at least a few of my glow plugs are bad too, but it's cold up here, 5 degrees and howling wind tonight, supposed to hit -15 Thursday night. I had my block heater plugged in and I did flip on the battery heater for a few minutes but got it started without much trouble.

I'm loving mine for plowing, but I gotta install a radio!

 

[Milbikes]

From what I have read in several posts, the 24V goes through a resistor that 'senses' the glow plug load, and adjusts the 24V to 12V, and works fine.........unless a glow plug or a few go bad, which raises the voltage load on the rest of the glow plugs...which burns another out....raises load etc. Finally, the card can be damaged. If I have interpreted the posts wrong, I will leave it stock, but I have seen that several knowledgeable individuals have made this mod. H.

 

[doghead]

Milbikes, you have it understood correctly. (mostly)

So, if you resupply the gp relay with 12v, the glow plugs can die off one at a time, without taking the others out.

That is reason enough for me.

 

[doghead]

I found a description of the mod (24 volts glow plug feed swap to 12volt feed) but a picture would really help. H.

sorry, it's too cold to go out and take a picture right now. Here's a quick picture that should help you visualize what you need to do to resupply the gp relay with 12 volts.

You can achieve this several ways(cut the red wire and add a new 1/4" ring terminal at the red X, disconnect the red wire at the red circle and drill the terminal big enough to fit on the stud, or simply disconnect the red wire at the GP relay and make a new wire with ring terminals at both ends).

The straight solid red line shows where you need to connect to.

Personally, I disconnected the original red wire at the relay end. Taped over the end and left it there in case I want to go back to original someday. Then I made a new wire and installed it.

 

[mgramann]

sorry, it's too cold to go out and take a picture right now. Here's a quick picture that should help you visualize what you need to do to resupply the gp relay with 12 volts.

You can achieve this several ways(cut the red wire and add a new 1/4" ring terminal at the red X, disconnect the red wire at the red circle and drill the terminal big enough to fit on the stud, or simply disconnect the red wire at the GP relay and make a new wire with ring terminals at both ends).

The straight solid red line shows where you need to connect to.

Personally, I disconnected the original red wire at the relay end. Taped over the end and left it there in case I want to go back to original someday. Then I made a new wire and installed it.

Doghead, have you heard of any situations where the military bypassed the resistor? If I remember right, I have a wire coming directly from the battery to the GP relay to provide 12V-and that's the way it was when I picked it up after the auction.

 

[doghead]

Anything is possible, in the military!

 

[Wolf.Dose]

At some 120,000 miles the controller carts for the pre glow start to fail. Plugs need a max glowing time of 6 seconds, else they overheat, if the card does not ad addidional registers. There is no regulator coil in the plugs. The Hummer plugs with 24 V have regulator coils incorporated. To change to 24 plugs you have to change the contact shoes. Glowing then takes about 50 to 60 seconds (timer helpfull).
Hope this helps.
Wolf
By the way, my coldest start with a 6.2 l Diesel was at some -22°C.

 

[Milbikes]

Doghead, thanks very much for the picture. Along with your description it will be a snap. I will make a new wire, and preserve the original. I picked up the AC 60G plugs tonight, and may tackle the job tomorrow. Is it best to do this with the engine hot, or cold? At least I can see the glow plugs in the M1008. In my 6.5 Suburban, the passenger side is nearly impossible unless I remove a lot of parts. H.

 

[doghead]

I have changed all my GPs cold.