My A/C cools half the time. Blows cold for a few minutes then blows haot air for a few minutes. I took to a mechanic who sent me to buy a electronic thermostat that goes in the evaporator ($100.00) but still doing the same thing. Anyone have this problem before. Its like the compressor is cycling to often.

 

I had a similar problem, make sure that the fan for your condensor is working.At idle, my ac clutch was cycling.

 

i never had same problems but i think the problem is more of on your cooling system... this system is essential to keep your engine from overheating. when the fuel is burned, the power is produced. when heat build up, the temp will become high when some of your auto vehicles part will melt, making it immobile... but the presence of your cooling system keeps it on operational level.. like the mercedes fan clutch, whenever the temperature rise again to a critical level, air is blown over the radiator reducing the heat of the coolant...

 

Sounds like you're low on refrigerant or possibly have a weak expansion valve. Having too much compressor oil in the system can cause similar results.

I would take it to an A/C technician and get his opinion.

 

My '99 EX is doing the same thing, I took it to a A/C shop and told me it was the A/C compressor clutch. They quoted me $90 to replace it.

 

That actually sounds like a pretty decent deal there, Solid_Snake. Which is exactly why you go to a shop that specializes instead of a general maintenance mechanic. I had similar issues with my '82 Mustang and took it to a GoodYear shop, who basically charged me a ton of money, broke the cast aluminum bracket that held my A/C compressor, and never actually did fix the real problem. They also never 'fessed up to breaking the bracket either... although they did attempt to fix it with JB Weld. Yeah, that made it better.

 

First thing you want to do when diagnosing an A/C problem is to check the compressor clutch. When the A/C is not working but it should be working, check to see if the clutch is engaged or not. You can check this by looking to see if the entire A/C compressor pulley is turning. If the inside part is not turning, the clutch is not engaged. If the clutch is not engaged, but should be, you must check to make sure the clutch is actually recieving power. The A/C clutch is an electromagnetic clutch meaning that it is a coil of wire. When the coil recieves power, it pulls all the parts of the pulley together and turns the compressor. If your clutch is recieving power but is not engaging, there is something wrong with the clutch. If the clutch is not recieving power, there is something wrong with the A/C system. Check the A/C pressure switch and the A/C thermostat. If you need schematic diagrams, I can provide them. I haven't actually looked up the A/C system in your car so I don't know exactly how the clutch is controlled. I believe there is a relay that controls power to the A/C. The relay is controlled by the controls inside the cabin. There are also several sensors that control the relay as well such as the pressure switch and the thermostat. If the pressure switch detects low pressure, it will shut the power to the compressor off. If the thermostat detects the temp is too low, it will shut the power to the compressor. The thermostat will be constantly turning the compressor on and off. Once the A/C has reached a certain temp, the compressor will shut off. The A/C will began to warm up and the compressor will turn on again. It is a never ending cycle. The pressure switch should not be cycling. The pressure switch looks at the pressure in the system and if it is off the switch will turn the A/C off. There should be a reciever/drier (check near the condensor). The reciever/drier might have a glass window towards the top. Check this window for bubbles. The bubbles mean that the system is low on refrigerant. If there are no bubbles, than the refrigerant level is fine. Another way to check to see if the pressure switch is turning your compressor off is to take the connector out and short it with a paper clip. If the compressor clutch engages after you short the connector then there is something wrong with the pressure switch or the pressure in the A/C that is causing the malfunction. This does not automatically mean that the pressure switch is not good. In fact, the pressure switch may be fine since the A/C works at first. The pressure switch might trip after some time due to a problem with the pressure in the system. If you have any questions, feel free to ask.