AC blows cold then hot

[AVMotorcycles]

Hey guys I’m having a problem with my AC and I’m at an impasse.
I started having issues with my AC blowing cold for awhile and then it blows hot.
I recently replaced my water pump as it was leaking and I knew that improper engine cooling can contribute to overheating but it didn’t help at all.
I’ve made several repairs not because of the AC but just because they needed done and it’s; water pump, fan (not the electric one) and fan clutch, ac pressure sensor.

I’ve checked and my ac clutch does stop spinning after the truck gets warm/hot but my temp gauge never gets past 1/4 on the dash. Aside from replacing the electric fan (which does run as soon as I turn the ac on) I don’t know how else to proceed except take it into a shop.

Also for context I am a trained and certified motorcycle technician and have all my own tools and everything I need in my garage so I am able to make most repairs, I just lack years of experience and the knowledge of AC systems.

 

[Fast69Mopar]

Hey guys I’m having a problem with my AC and I’m at an impasse.
I started having issues with my AC blowing cold for awhile and then it blows hot.
I recently replaced my water pump as it was leaking and I knew that improper engine cooling can contribute to overheating but it didn’t help at all.
I’ve made several repairs not because of the AC but just because they needed done and it’s; water pump, fan (not the electric one) and fan clutch, ac pressure sensor.

I’ve checked and my ac clutch does stop spinning after the truck gets warm/hot but my temp gauge never gets past 1/4 on the dash. Aside from replacing the electric fan (which does run as soon as I turn the ac on) I don’t know how else to proceed except take it into a shop.

Also for context I am a trained and certified motorcycle technician and have all my own tools and everything I need in my garage so I am able to make most repairs, I just lack years of experience and the knowledge of AC systems.

What is the year/model/engine of your truck?

 

[AVMotorcycles]

It’s a 2011 ram 1500 with the 5.7 hemi

 

[MarshRam]

When it blows hot have you checked to see if the AC clutch is engaged?

 

[turkeybird56]

When it blows hot have you checked to see if the AC clutch is engaged?

@MarshRam
@Wild one

Reread his post. He says in his original post that the clutch stops spinning when truck gets hot may explain why his AC “not” working. I had to reread to get wat OP saying. I am not HVAC or AC tech cannot offer advice. If it was a 70s system I would say thermal fuse bad. But that is old style Delco Systems.

 

[AVMotorcycles]

When it blows hot have you checked to see if the AC clutch is engaged?

Clutch disengages.
I’m sure it’s an overheating issue and that the clutch is disengaging because it can’t cool properly, but I don’t know why.

 

[MarshRam]

Clutch disengages.
I’m sure it’s an overheating issue and that the clutch is disengaging because it can’t cool properly, but I don’t know why.

We found a source to focus on, good news!!! Bad News: I'm probably of less help moving forward. I have no idea if the AC clutch can intermittently go out on a "slowly" failing clutch or if they always just completely fail with no warning. So can't say you need to replace it, but we have a starting point. Could be a grounding issue, a relay, or something else. As many details as you can provide would be helpful. There are folks on here that have experience and can most likely nail it down and they might send you to do some tests! More details you give them, the more info they have to figure it out. I have no idea here, but my next question would be is there a frequency to the issue? Such as, happens so long after starting it up, it's sporadic, etc.. Good luck man!

 

[Markw]

You probably have a bad electric fan. There is an electric fan on the engine side of the radiator. If it is not functioning properly you can have air conditioning problems when stopped. Not enough air is being pulled through the condenser and radiator. Make sure it comes on. Also you probably need to replace the fan clutch if it’s never been replaced before. I have a 2012 and had to replace the radiator earlier this year and one of the things I replaced was the fan clutch. I replaced the electric fan a couple of years ago when my air conditioner started acting up.

 

[AVMotorcycles]

You probably have a bad electric fan. There is an electric fan on the engine side of the radiator. If it is not functioning properly you can have air conditioning problems when stopped. Not enough air is being pulled through the condenser and radiator. Make sure it comes on. Also you probably need to replace the fan clutch if it’s never been replaced before. I have a 2012 and had to replace the radiator earlier this year and one of the things I replaced was the fan clutch. I replaced the electric fan a couple of years ago when my air conditioner started acting up.

The fan definitely works because I hear it kick on when I turn on the AC. However it might need to be replaced regardless. I’ve also already replaced the fan clutch and the fan that attaches onto it along with the water pump.

 

[Ritchie_Rich]

Sounds like low pressure due to low refrigerant.