Manual Heater Shutoff Valve? My feet can’t take the heat!

[One65r]

New M38a1 owner. Got it a couple months back and I’m waiting on my manuals I bought from KW. I have been enjoying driving it around so much that I hadn’t paid much attention to the heater blowing on my feet and out of the heater Box between the seats. Plus I’m in MS and it’s already a heat index of 110 so in theory if it gets any hotter my heater will feel like an AC.

The manual heater shutoff valve is locked up and stuck open so I have a new one coming in tomorrow. When I install this, I know it’ll fix the heat blowing on my feet. Will it also fix the heat being generated in the heater between the seat?

I honestly thought that heater was electric and I unhooked the wire going to it. Yesterday I realized the box was still heating up and the wire I unhooked must have just been for the fan motor. I noticed there are 2 hard lines running back to it so I’m guessing that’s hot coolant or something to generate heat in it?

Thanks in advance for any info. My toes are gonna look like roasted Vienna sausages if I drive around in flip flops again

[LarrBeard]

Here is a quick link to the M38A1 Tech Manual:

https://willysjeepforum.kaiserwillys.com/showthread.php?2277-TM9-8014-1-4-Ton-4x4-Utility-Truck-M38A1-and-1-4-Ton-4x4-Front-Line-Ambulance-M170

There were enough variations of the M38A1 to always keep things interesting. In the TM9-8014 nothing is mentioned about a heater in either the cooling or electrical sections - you just put on a bigger coat.

On just about everything, engine coolant is used as driver heat - so shutting off the coolant should do the trick. Of course, because Jeeps of every name and age are such perverse critters, you could just have a hole with hot air from the exhaust system and road blowing around.

We've never discussed this before - are there versions of the M38A1 with heaters?

[One65r]

I had tried the "search" feature for topics related to this on the forum but it gave me a bunch of random threads. I had briefly looked up under the floorboard to see where all that heat was coming from but didn't see anything obvious. I'll look again tonight. It'd have to be one hell of a hole with all this heat I've been feeling. Is there really not some sort of heater that blows down on the drivers feet?

[bmorgil]

Any luck on your "heat on the feat" issue? You can always by pass the heater core by running the water hose from the valve on the block straight to the water pump. I think the best way is to fix the stuck valve and shut it off there. It sounds like everything is working great on the heater. A very nice option to have when it actually is in working condition. Take some pictures of what you are working on. It will help determine if you have a "factory heater" or an add on.

[LarrBeard]

It will help determine if you have a "factory heater" or an add on.

Once again, it is strange how we end up on the same topic at the same time. We had never talked about M38A1 heaters until we had the "stuck valve" post and it made us wonder if M38A1's had original equipment heaters.

Then, just a day or later, we had a picture of another vehicle (most likely a modified M38A1) with a heater. Once again - is it an original or add-on?

More pictures please.

[gmwillys]

The heaters were part of the Arctic kit. They were add on retrofit kits for the units going to extreme climates. The kit would consist of an artic hard cab and doors, and a heater. Most were unit installed instead of factory.

[LarrBeard]

The heaters were part of the Arctic kit. They were add on retrofit kits for the units going to extreme climates. The kit would consist of an artic hard cab and doors, and a heater. Most were unit installed instead of factory.

OK - would they have looked like this?

[gmwillys]

Yes. The passenger side was taken up with the battery box in the cowl and doesn't leave much room. The heater core was in the engine compartment within the heater box to be able to retain the glove box.

There is another Arctic extreme kit available for the M38/M38A1 that utilizes a fuel fired heater. The heater you have is the hot water heater

https://jeep1942.com/?page_id=4874