I have a black car (98 EX MT) and its reaching near 90 outside now and I have a little one so I have to resolve the a/c issue now. Any help on this would be appreciated.

Now a rough idle may also be the cause of this but I am going to clean my engine and iacv accordingly per instructions... just wanted to let you know before I go further.

The problem happens when the car is idling, you hear a switch click and the rps drop and make my tach bounce along with it. Once this happens the a/c starts blowing hot air. It starts blowing ICE cold when I take off and start driving again but the power in the car decreases dramatically, I know that ac's suck power but this is rediculous almost feels like the motor is running just for the a/c. I have attempted to hook up one of those refrigerant cans with the gauges on the top and the needle goes straight to the red everytime and wont even pump the refrigerant into the compressor. Any ideas?

 

You need to hook up A/C manifold gauges to the system to measure pressure on the low and high side. I think your system is overcharged with refrigerant, which can destroy the compressor, if this has not already happened.

 

That sounds logical never really thought of it that way...also by the way freon actually never even pumped out of the can into the compressor it wouldnt suck it in at all, this sounds like another messup from the previous owner (overcharging)... Also, Autozone has these tools for rent near my location. Do you know what the pressure needs to read? And do I have to take it somewhere for them to release some of the freon if this is the case?

 

By the way, your system requires R134a refrigerant. The gauges must be designed for this specific refrigerant. Values below are R134a PSI on the low versus high side with the engine idling and the A/C running.

If the system is overfilled, the excess must be drained. I think this is best done by a local shop. Some oil change places offer this service.

 

Make sure the condenser fan works. The fan not working will cause the A/C to cut out when the car is sitting still but it will start up and cool when the car is moving because you don't need a fan then.

If the engine idle drops below normal (for whatever reason) the compressor will drop out to prevent stalling. This could be a tune-up problem or because the compressor is drawing too much horsepower due to overcharging.

Charging with cans only works when the compressor is engaged. It is easy to overcharge because the total capacity (from completely empty) is only about 1.5 cans (18 oz). The only way to be sure of a proper charge is to have all the refrigerant removed (down to a vacuum, using a vacuum pump) then recharge by weight.

 

You were right about the condenser fan! I unplugged the connector and ran it with my dewalt 12v battery (after measured no current upon switching) and the a/c stopped clicking and the inside cooled down (artic)! Is this a simple fix? What would the cause of this be? Its gotta be as simple as something as a switch right? Im going to go to autozone and try out a new relay, just in case that doesnt work any ideas?

 

 

how do I test the relay, I have voltmeter.

 

 

RonJ thank you sooooooooooooooooooooooooooooooooooooooooooooooooo ooooooooooooooooooooooooooooooooooooooooooooooooo much for your help on this issue. I found the problem, it was my condenser ground. IT WASNT EVEN BOLTED ON! My car is right in front of me now purring and popping like it should and the interior of my car couldnt be colder! Me and my little girl both thank you for your help on this! I am becoming more amazed by this site every single day!