A/C compressor clutch

[cordobaman1975]

1975 Cordoba. AC completely renovated. Compressor clutch hangs up (stops turning) when engaged during low RPMs or at idle. Driving at higher RPMs the engaged clutch does not hang up/stop turning and system cools perfectly.What is causing clutch hang up at idle/low RPM? Thanks. Tim

 

[MoparLeo]

Describe what you mean by "clutch hangup" ?

 

[Demonic]

? Not sure what you mean by "hangs up." As a temporary test, you could jump 12v to the clutch coil wire, easy test. 1975 would have a low pressure switch. 60 deg - if that's the discharge air - is on the warm side, unless you're around 80 deg wet bulb temperature, aka, humid.

 

[Demonic]

Ha, Leo posted while I was getting iced tea.

 

[MoparLeo]

Looks he is from So Cal. 60 ° is ok if it is 80-90° . Most people don't know how A/C works. It does not cool down the air, it removes heat from it. So its efficiency depends on the ambient temp and humidity. Since it is a radiator it needs airflow through the condenser to work. The higher the airflow the more heat it removes. When you test your a/c, put a fan in front of the radiator at its highest speed setting to get more accurate temps and pressures.
60° feels real cold when it is 90° outside. Don't expect 30-40 ° temps ever from the vents. The compressor is the most inefficient at idle and low speeds. It needs pressure and airflow to work properly. If you are not familiar with a/c work and/or don't have a set of gauges. Aren't sure of the amount of refrigerant that is in the system, you should have it professionally checked. It is like trying to diagnose an electrical problem with out knowing if the battery is fully charged.

 

[cordobaman1975]

? Not sure what you mean by "hangs up." As a temporary test, you could jump 12v to the clutch coil wire, easy test. 1975 would have a low pressure switch. 60 deg - if that's the discharge air - is on the warm side, unless you're around 80 deg wet bulb temperature, aka, humid.

Revised the post. Everything is new in the a/c system. Clutch coil works correctly. This one has my scratch in my head.

 

[MoparLeo]

Did you bypass the low pressure switch to check the clutch ? It is normal for the clutch to cycle ( turn on and off) at low speed/idle.
Did you take it to an A/C shop to have it checked yet? You can't diagnose on line.
You need the experience and proper tools to do this. It won't cost very much if that is your issue to have it checked. And it will cost much less to fix it right the first time rather than doing a lot of guessing.

 

[Demonic]

Likely nothing is wrong, as Leo said. Assuming the system was not leaking, properly evacuated, and the charge is correct.

 

[RJRENTON]

Looks he is from So Cal. 60 ° is ok if it is 80-90° . Most people don't know how A/C works. It does not cool down the air, it removes heat from it. So its efficiency depends on the ambient temp and humidity. Since it is a radiator it needs airflow through the condenser to work. The higher the airflow the more heat it removes. When you test your a/c, put a fan in front of the radiator at its highest speed setting to get more accurate temps and pressures.
60° feels real cold when it is 90° outside. Don't expect 30-40 ° temps ever from the vents. The compressor is the most inefficient at idle and low speeds. It needs pressure and airflow to work properly. If you are not familiar with a/c work and/or don't have a set of gauges. Aren't sure of the amount of refrigerant that is in the system, you should have it professionally checked. It is like trying to diagnose an electrical problem with out knowing if the battery is fully charged.

ABSOLUTELY CORRECT.....
Your supposition that, most people, do not know, or understand, how an Air Conditioning/refrigerant system works.....only what an acquaint or "buddy" has told them incorrectly. Thermodynamics is an exact science that requires a basic understanding of the process....not hearsay.
BOB RENTON