Intermittant Air Condtioning


#1

The air conditioning starts out cold, warms up after 5-10 minutes, then gets cold again after 5-10 minutes, etc.

My mechanic wants to replace the condenser, but he’s guided by reckoning and has missed the boad in the past.


#2

Try a shop that specializes in automotive AC systems.


#3

Thank you for your response. I plan to do that, but would like to have some ideas as to what the problem could be.


#4

Raleigh, keep in mind that properly operating A/C systems require adequate volume of refrigerant, a closed, non-leaking ventilation system, properly operating compressor/clutch, compressor relay(s) and evaporator, and unrestricted airflow across the condenser/radiator. It may be as simple as low refrigerant level or failing pressure sensor cutting off the compressor erratically. Then again, it may not. A trusted full service indy or automotive A/C shop can sort it out.


#5

The coolant has been evacuated and been replaced. I was hoping that it could be a sensor I could check/replace. It’s too complex to guess at. I’ll take it to an expert next week. I just didn’t trust my mechanic on this one and was hoping someone would dispute his condenser verdict. Thank you for your response.


#6

Raleigh, Don’t take this wrong I am not harping on terminology,its just that other people read these posts,your AC system uses a refridgerant not a coolant.


#7

Unfortunately, it isn’t sensor-based.

What happens when you turn the AC on is that the clutch for the AC compressor is energized and the pump begins to push refridgerant. The refridgerant is compressed into the condensor, becoming hot as it’s compressed. All matter becomes hot under compression.

Moving through the condensor, which is like a radiator, the heat is removed.

The compressed refridgerant, now at (ideally) ambient temperature, is then allowed to rapidly expand in the evaporator. When it does so, it becomes chilled, again just basic thermodynamics, basic energy conservation.

The cabin air is blown through the chilled evaporator, where the chilled evaporator core pulls the heat from it (cools it). The cabin air as it’s cooled also releases its moisture as condensation on the evaporator core. The condensation gathers and runs off. The now cooler and drier cabin air is pumped back into the cabin by the blower.

The refridgerant, now carrying heat from the cabin air, goes back to the compressor where it begins the whole cycle again.

As you can see, there’s really no sensors to check that might make repair easy. It’s just circulating refridgerant being compressed and decompressed over and over, taking heat from the cabin in the evaporator and having heat dissipated into the outside air in the condensor.