I've looked around, but no one seems to have had the exact same problem or solution to mine. I have a 99 Accord Coupe EX. The AC blows plain old air more often that it blows cold air, which can be very problematic on really hot days or when it's raining. Freon is not the problem, so I thought I would check online before I attempt to do anything or take my car to another shop. I appreciate any help on the issue.

 

How do you know refrigerant is not the issue? Too much can probably lead to high-pressure switch cutting it out.

 

Brought it to a mechanic and he tried to add the coolant but the sensors let him know that it was full. No Coolant had been added to the since I bought it in '05. This problem started around summer '07, but I've been getting by(Trying to avoid spending too much money). So you're saying that draining some may be one solution?

 

No, I'd rather say that you should measure both high & low side pressures so you know where you're starting from. Just adding (or just removing) refrigerant sounds like you're flailing rather than figuring it out. You say the mechanic tried adding refrigerant, but maybe you don't know which sensors "let him know" that it was full. If the mechanic based that on measuring both high & low side pressures, then maybe he's correct. Your first post didn't say much about that, so I assumed the worst - that you had just added a can of refrigerant without measuring anything.

It might be cutting out because of high pressures, maybe because of low pressures, maybe because of a faulty anti-freeze thermistor, etc... You might want to figure out WHICH sensor is causing it to cut out. Or maybe it's cutting out because of intermittent contact somewhere in the circuit. Or maybe the expansion valve is blocked by crud (which causes the high-pressure to be too high while the low-pressure is too low).

Sometimes you have to evacuate the AC system & add refrigerant back in by weight. There's other people on here who know a lot more about AC than me, so let's see if they chime in.

 

Wow, I didn't expect that there could be so many different possibilities. The mechanism used by the mechanic adds coolant, but only if the gauges detect that the coolant is low. The device looks like the one in this picture but had a much bigger tank connected to it. When I said sensors, I meant gauges. No coolant was blindly added,

I guess I'm heading to AAMCO for that free AC check. Unless someone else has any pointers.

Thanks Jim

 

I guess a good mechanic would have checked at least some of those other possibilities, whether he explained it to you or not.

It's one thing for his charging system to refuse adding refrigerant based on pressures. Besides that, there's several sensors built into the AC system that prevents it from running - one of THOSE sensors might be the problem to begin with. First you (or the mechanic) find out which sensor makes it shut down. Then figure out whether the sensor is bad or whether it's correctly measuring somthing that causes it to shut down before destroying itself.

I used to have a 98 Accord & I had the Helm shop manual. Never had AC problems, but the section about troubleshooting the AC was probably 80 pages...

 

Thanks again. I will let you know what the end result is.

 

A/C systems aren't too complicated to do some initial tests.

When the engine is running, the clutch plate that sits outside of the a/c pulley should not spin with the air turned off. When your turn on the a/c, the clutch plate should engage and spin with the pulley. Also both fans on the radiator should turn on.

If the clutch plate does not engage, turn off the car, unplug the electrical connector going to the compressor. Start the car and turn on the a/c. The wire going to the compressor should have 12V to body ground. Let us know what you find.