A/C compressor not disengaging in heavy traffic and hot day

**tonyboy** · April 25th, 2016 10:42 AM

Hi sirs,

Just had my car compressor replaced about 2 months ago. My issues is when in heavy traffic and on a hot day around lunch time, the compressor does not seem to disengage to the point of 1 time overheating in EDSA at 1 pm.

Morning, afternoon or evening it’s automatically engaging/disengaging. Brought it back to the a/c shop and according to them the system seems ok.

Any ideas why it’s not disengaging when in heavy traffic and on a hot day?

Thanks!

**oj88** · April 25th, 2016 11:19 AM

To me, the A/C is working normally.

What car?
What setting did you set the A/C thermostat to?

On a hot day, it's normal for the A/C to work harder to maintain the temperature inside the cabin. But no matter what, the A/C should not cause the engine to overheat. Something else is then inherently wrong with the engine's cooling system. Check radiator fans, coolant level and condition, engine thermostat valve condition, radiator, etc.

**tonyboy** · April 25th, 2016 11:29 AM

Originally Posted by oj88

To me, the A/C is working normally.

What car?
What setting did you set the A/C thermostat to?

On a hot day, it's normal for the A/C to work harder to maintain the temperature inside the cabin. But no matter what, the A/C should not cause the engine to overheat. Something else is then inherently wrong with the engine's cooling system. Check radiator fans, coolant level and condition, engine thermostat valve condition, radiator, etc.

Hi sir,

Thanks for your input.

Honda City 2004. Thermostat is set to about 70%.

**tonyboy** · October 3rd, 2016 10:10 AM

Sirs, update lang on this. My air con's working fine now but I have another issue:

Few minutes after staring the car I notice that my compressor is short cycling or it's rapidly turning on and off (1 second on - 1 second off). After the engine has fully warmed up it operates normally.

Ano kaya possible cause nito? Brought it to an AC tech and said that my the evaporator thermostat is faulty. Any thoughts?

Thanks!

**oj88** · October 3rd, 2016 10:51 AM

Originally Posted by tonyboy

Sirs, update lang on this. My air con's working fine now but I have another issue:

Few minutes after staring the car I notice that my compressor is short cycling or it's rapidly turning on and off (1 second on - 1 second off). After the engine has fully warmed up it operates normally.

Ano kaya possible cause nito? Brought it to an AC tech and said that my the evaporator thermostat is faulty. Any thoughts?

Thanks!

Is the RPM fluctuating or abnormally low while the engine is still cold?

Most engine ECUs would disengage the A/C compressor when it detects that the engine is about to stall and then re-engage it when it reaches a high-enough RPM.