HMMWV M1152A1 No Heat or A/C issue

Hey guys/Gals, I have an 1152A1 HMMWV that is having AC and heat related issues. When I have the low pressure cut out switch plugged in the inside circulation fan in the cab wont run except in heat, and the compressor also will not cycle. I can't get the heat to work on this vehicle also, can anyone please help me out with this issue????

Jsampo85 said:

Hey guys/Gals, I have an 1152A1 HMMWV that is having AC and heat related issues. When I have the low pressure cut out switch plugged in the inside circulation fan in the cab wont run except in heat, and the compressor also will not cycle. I can't get the heat to work on this vehicle also, can anyone please help me out with this issue????

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Sounds like 2 separate issues. I can’t help with the AC but i had no heat with the fan running in my M998. I had to unhook the heater core lines and flush back and forth to remove tons of rust. I also let CLR soak in the core and that fixed it. Heat works well now. Also make sure your heater valve on the heater hose is actually opening fully.

if you have an electric water valve, it is normally open. When you switch to a/c, it takes a minute for it to close. Watch to see that it moves when someone else switches from heat to a/c. or the other way.

Jsampo85 said:

Hey guys/Gals, I have an 1152A1 HMMWV that is having AC and heat related issues. When I have the low pressure cut out switch plugged in the inside circulation fan in the cab wont run except in heat, and the compressor also will not cycle. I can't get the heat to work on this vehicle also, can anyone please help me out with this issue????

Click to expand...

Our shop specializes in OEM A/C on the HMMWV, that and the M11XX series vehicles....feel free to reach out to our shop.

I know this is an old thread but…..wondering if anyone knows of common places for A/C leaks for the M1165A1? I got the system charged with 3lbs 8oz and it’s blowing cold but low pressure won’t go above 20lbs. it sat for 5-6 years in storage and I’m guessing some seals dried out and it won’t hold pressure. Once I got it to 20lbs I let it sit for a couple hours and it leaked down to 10 and compressor cuts on and off.