taskunitbruiser
Active member
- 106
- 50
- 28
- Location
- Alabama
I wasn't finding anything useful on YouTube and searches on here did not help much either. While I have fairly decent mechanic skills and a few good tools, I am pretty clueless when it comes to A/C systems on cars (successfully replaced capacitor on home A/C before! haha). I need help.
When I bought my M1151A1 (factory equipped A/C) it blew cold air in the back (i.e. box between rear seats) and hot air up front. I deduced I likely had proper refrigerant levels, etc since I was getting cold air in the back. It may just be a separate system however, yet I get cold air "leak" out of the plastic housing on the passenger side front. I have no gauges to test anything. Mike at Black Dog told me Humvees have some thermal expansion type ball under the hood to select between heat and cold if I remember correctly. So, the engine coolant was heating up my nice cold air, simply overwhelming it. There is no rear heat in my HMMWV, just a/c. My father in law drives big rigs and says those trucks have a manual selector between heat and a/c under the hood; in other words, find out what you need before you start driving.
Mike said this ball falls and if you replace it it will fail again in 6 months. The solution is to put a manual valve to replace it. Has anyone here done this? More recently, my rear a/c box quit blowing air (i.e. no airflow [more problems]) but I get great heat up front, so fan is working there. Can someone tell me where this selector ball is, where to cut it out, and what type of valve to get for replacement? Again, not to be verbose, but I just don't know much about a/c's and have yet to find where this part is located. The TMs I looked at do not cover A/c, but maybe I missed one that does.
Can this be replaced without recharging the system? How big of a project will this be?
When I bought my M1151A1 (factory equipped A/C) it blew cold air in the back (i.e. box between rear seats) and hot air up front. I deduced I likely had proper refrigerant levels, etc since I was getting cold air in the back. It may just be a separate system however, yet I get cold air "leak" out of the plastic housing on the passenger side front. I have no gauges to test anything. Mike at Black Dog told me Humvees have some thermal expansion type ball under the hood to select between heat and cold if I remember correctly. So, the engine coolant was heating up my nice cold air, simply overwhelming it. There is no rear heat in my HMMWV, just a/c. My father in law drives big rigs and says those trucks have a manual selector between heat and a/c under the hood; in other words, find out what you need before you start driving.
Mike said this ball falls and if you replace it it will fail again in 6 months. The solution is to put a manual valve to replace it. Has anyone here done this? More recently, my rear a/c box quit blowing air (i.e. no airflow [more problems]) but I get great heat up front, so fan is working there. Can someone tell me where this selector ball is, where to cut it out, and what type of valve to get for replacement? Again, not to be verbose, but I just don't know much about a/c's and have yet to find where this part is located. The TMs I looked at do not cover A/c, but maybe I missed one that does.
Can this be replaced without recharging the system? How big of a project will this be?
