Daily driver A/C issues

[timmycharger]

Any feedback is appreciated here. My wife's van, 2013 Chrysler Town and Country a/c not working.  It worked fine last summer and last week I tried it for the first time this year and nothing.

Put my manifold gauges on it and confirmed that there was no pressure in the system. I then tried pressing the valve on both the low and high ports and confirmed no pressure, empty.

I then put a vacuum pump on it and it held the -30 inHg for about 45 minutes with no change in the value after turning the pump off.

I then put the pump on again for 45 min to pull a vacuum again before then trying to add the 134A. 

The problem is no matter how many times I tried this process, I can't get the system to pull any Freon. I bled the air out with the little valve on the yellow refrigerant hose until it sprayed solid liquid. Still nothing.

I can't get the compressor to click on as I cant get anything to go into the system.

Any ideas why I cant get anything in the system? Did my sudden loss of Freon over the winter have anything to do with it? could the compressor be locked up?

[John_Kunkel]

After you have a vacuum in the system with the engine OFF and open both valves on the manifold set, do you see a pressure rise on the gauges? If you close both valves does the pressure remain for a while?

It takes about 40 psi in the system before the compressor clutch will engage. Sometimes you have to jumper the low pressure switch or run a wire directly from the battery to engage the compressor clutch until enough pressure builds up in the system.

I assume you are opening only the LOW side valve on the gauge set to charge the system.

[timmycharger]

After you have a vacuum in the system with the engine OFF and open both valves on the manifold set, do you see a pressure rise on the gauges? If you close both valves does the pressure remain for a while?

It takes about 40 psi in the system before the compressor clutch will engage. Sometimes you have to jumper the low pressure switch or run a wire directly from the battery to engage the compressor clutch until enough pressure builds up in the system.

I assume you are opening only the LOW side valve on the gauge set to charge the system.

Yes, I was trying to only put the Freon on the low side. 


I did not look at the gauges after I was done pulling the vacuum, it was still holding the -30. I then introduced the Freon thinking that the vacuum I created would pull the Freon into the system and trigger the compressor clutch.

First I opened the valve for the Freon to flow, I then opened the low side valve and had zero on the high side and about 50 PSI on the low side. It just stayed around there with the engine running for over 10 minutes with no Freon being sucked in.

[John_Kunkel]

I then introduced the Freon thinking that the vacuum I created would pull the Freon into the system and trigger the compressor clutch.

It should but, as I stated, sometimes it won't, so you have to jumper power to the clutch to get it going.

[timmycharger]

Thanks, John.

[John_Kunkel]

On modern cars, computers control everything...be careful applying power directly to the clutch, best to do it with the connector disconnected so there's no feedback to the computer.