stang_man98

'98 Mustang
Engine - 3.8L V6
Model - Standard Coupe

I have had this car for about two years now with close to 60k miles on it. A couple of weeks ago, I noticed all of the sudden the A/C just stopped working. By A/C, I mean the cooling function is not working as expected, the fan works fine.

I usually get freezing cold air when I crank all the settings up (HI fan, coldest air, MAX A/C). So after I noticed this change I figured it needed a coolant refill so got one of the larger coolant refill tanks (like at least 7 inches long) at the local Auto Parts store. Refilled it in the proper valve, and emptied the refill tank. It still was not cooling down the car. So I got two more small refill cans, and still nothing.

It puts out a little cool air when I first start it up (e.g., the engine temp dial shows it is cold as the car warms up), but once the car has been running for a bit, it is either room temp or hot air from the engine, no matter the fan location setting (floor, mix, vent, MAX A/C, etc), fan speed was maxed, and of course, coldest setting or just above it have been set.

All spark plugs under the dash look fine, and are not blown.

One thing I noticed before this occurred was that the MIX setting stopped functioning normally. It now only outputs to the floor and not out the middle vents that go to the face as well as it is suppose to.

I'm not a mechanical engineer or much a mechanic at all, but I figured it has something to do with the A/C control panel unless, of course, there is a leak in the A/C valve. Definitely willing to learn more about working with cars now that I have this issue.

Any ideas would be greatly appreciated.

Thanks for your time.

Mike

stang_man98

Anyone?

stang_man98

Does anyone need more information? I'd really like to deal with this issue. Thanks

bmaytum

Make sure your compressor is turning when the AC is on. If it is not, look to the clutch, the clutch controls, or a failure of the compressor itself. If it is turning, there are more items to check that I am fortunate not to know about.
How to check your system:
http://www.aa1car.com/library/air_co..._checklist.htm

I am concerned that you were able to get three refill cans in the AC. That suggests either serious leaking or that your system in now overloaded with Freon. Were you using one of the refill kits with a gage? That can indicate over/under full condition.

In my case, I put two cans of refill in mine and burned out the AC compressor clutch. Making sure the compressor is turning can help locate the problem. As soon as my clutch failed, the car would no longer make cold air. The clutch was an easy fix and cost $110 for parts.

good luck.

belairbrian

As mentioned, start by seeing if the compressor is engaging. When not engaged the outside part of the pulley turns but not the inside part.

If that's good make sure the electric fan on the radiator is turning. The fan at the radiator always runs when A/C is on.

If that is working feel the lines going through the firewall you should feel a difference.

If all that is good you need to look at the A/C controls. Normally they fail to defrost but they are vacuum operted and yes you could ahve a normally functioning A/C with the mix valve stuck in heat. In fact that would explain why you have some cooling until the engine warms up.

I'm guessing this should say fuses. "All spark plugs under the dash look fine, and are not blown."

SCJ521

If the compressor is working, which I highly doubt after 3 cans of refrigerant, but if it is check the low pressure side (pressure) with ac set to max car running, should be around 40 psi depending on temp outside. If slightly high you have too much in the system and the high pressure switch should cause compressor to turn off. If very high you could have a fixed orifice tube that isn't restricting pressure between low and high side. Final thought is your heater blend door isn't functioning although you set it to cold it may be not closing completly

07graygt

You definitly have way too much refrig. Unless you have a huge leak which I doubt because you would have noticed it not getting cold little bit at a time. My guess would be the blend door which changes from cold air to warm air. But like others said check to see if compressor engages if not check the pressure switch next. But definitly need to have the system recovered and filled to specks first.

stang_man98

Just a heads up for everyone. It was my compressor that had gone bad. The mechanic wasn't sure whether happen before or after the coolant refill. Thanks for all your help.

Daehawk

Probably went bad before your 3 can fill up. One of those cans should not have enough pressure to over fill it by that much.