M1009 Glow Plugs - Again

My M1009 had a manual glow plug switch installed when I got it. I want to bypass the firewall resistor bank, but I recently replaced the starter with a good 24V unit and I have no intention of replacing it again anytime soon. At least one of my glow plugs is bad, and I want to replace them all while I am at it and avoid any future problems.

I am trying to decide between getting a set of Delco AC60G and wiring the plugs to the 12V tap on the firewall, or using Delco AC15G for a HMMWV and wiring to the 24V tap. I am not afraid to change the connectors for the glow plugs, and I really like the idea of powering the plugs off both batteries. Is there any reason I should use the 12v plugs instead of 24v?

Yes concerning 12 over 24 volt.

?? Concerning resistor or no resistor.

This topic is like a huge Ford/Chevy/Dodge debate. It goes on forever and there is no right answer for everyone. no matter which way you go. The 24 volt starter can stay.

12 volt with firewall resistor removed. Self regulating glow plug and most auto parts stores have them in stock. No chance of cascading failure. However, the front battery does all the work.

12 volt with firewall resistor in the system means both batteries are used and you can still use the self regulating glow plugs.

Either way concerning the resistor. Since you have the manual button. I would suggest the 60g glow plugs so you don’t pop one.

Speaking of the button. The system when working is much, much better than just a button. Spending the time, effort and money to be back on an automatic set up will really help if the temperature is below 70°.

12 or 24 volt hasn’t been discussed much. I am pretty sure it is technically possible to go straight 24 volt with no resistor. The glow plug relay will pass 12 or 24 through it just fine. The orange and green glow plug wires will work just fine either way as well.

Do as you wish. After 25 years and countless CUCV's I still use the 13 G AC Delco and have the entire system stock. And that is all I am going to say about it. Do NOT use Wellman glow plugs. Or you can I won't. The 13G are still available and I seldom change them.

79Vette said:

Is there any reason I should use the 12v plugs instead of 24v?

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None that I can think of, other than the obvious issue of price and availability, but you've already considered that.

The big GP relay is quite capable of handing the 24v, and it's controlled by 12v. Don't change anything on the control side of the relay (the two smaller terminals).
I don't know why the military didn't just do it that way in the first place. 24v start/GP system, 12v everything else. No heater on the firewall to make people panic when they see smoke coming out of it because some bug decided to nest there last night.

But I don't know why everyone makes such a big deal out of the imbalanced load on the two batteries. It's not like keeping it stock makes them balanced. Unless you convert all the other 12v parts (lights, blower motors, etc), it's still going to be imbalanced. Enough people have done the resistor bypass for enough years that I think it's pretty well proven to work well over time. All the doom and gloom has been proven wrong, so....

But either way will work for you.

cucvrus said:

Do NOT use Wellman glow plugs. Or you can I won't. .

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What? You don't like Swellman glow plugs?

Yeah, this past weekend I did the resister bypass (running a wire directly to the battery and not using the 12v tap on the firewall). Then installed a set of Kennedy Diesel Quick Heat glow plugs. It had the original Wellman plugs which luckily did not give me any removal issues but they only had 15K miles on them. Everything is working great and no need to worry about this again.

Kennedy Diesel Quick Heat glow plugs used to be rebadged Swellmans. The Kennedy website said so. No mention of that on their site now, so I don't know if they still are.

If they are not, they're rebadged something else.

chevymike said:

Yeah, this past weekend I did the resister bypass (running a wire directly to the battery and not using the 12v tap on the firewall). Then installed a set of Kennedy Diesel Quick Heat glow plugs. It had the original Wellman plugs which luckily did not give me any removal issues but they only had 15K miles on them. Everything is working great and no need to worry about this again.

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Everyone that runs the ACDELCO 13Gs and 60Gs have had extremely good and proven results.
Why go with anything else?
The Delcos aren’t expensive.
AC 60Gs are what the majority of guys use.
Self regulating and no swelling.

Once you have had to pull the injector(s) to remove the busted end of a swollen glow plug, you’ll understand why almost everyone uses the ACDELCOs.