A/C not working

[dexadel]

I have a 2004 and within the past few weeks the a/c progressively blew warmer and then finally wasn't blowing cold at all.

I got some r134 and put some in, but it was already topped off, so it blew the excess out the pressure relief valve on the bottom. The coolant is full.

Took it to a mechanic and they said the radiator/a/c fan wasn't working, and that is why it blows warm air. They wanted $550 for the job, so I bought the fan myself for $100 and put it in in 1 hour. Easy job. However- the a/c still doesn't blow cold.

The mechanic had told me that the compressor and everything else is working fine. The low pressure switch is working. The clutch engages.

What else could it be? My wife and child are roasting driving it around here in 100 degree weather every day. We don't have an a/c shop here, and based on the last time I took it in, I don't trust they'll get right to the problem without changing everything out to see what the issue was.... a few hundred dollars later.

The Haynes manual seems useless. Not much troubleshooting in it for a/c's.

[fritz_t_coyote]

quick troubleshoot:

hood up, engine running, have helper turn AC on: Does compressor engage and idle jump?

Y/N

if N: check fuses for AC.

if Y:
Compressor is running... 2 AC hoses run to the firewall... one hot, one cold.
Is the cold hose getting cold?
if N: Compressor/condensor fault?

If Y:
try twiddling the interior knobs: turn off 'recirculate'?
try DEFROST or HEAT to see if you get cold air.

Also: check for blocked cowl intake/clogged filter?

AND: make sure HEATER HOSES are cool. if heater valve stuck open will negate the chill of the AC.

[dexadel]

I thought the compressor was kicking on. But when I just turned the ac on with the engine idling- there was no change in the idle whatsoever. It doesn't seem now that the comressor engages.... the fuse is fine. Unless there's another fuse inline somewhere I haven't seen.

The compressor was engaging the first time I took a look at it when I added the coolant. Now it doesn't seem to.

[cocojaja]

check out the schraeder valve ! May need replacing. May be leaking.

[slartyblarfast]

More than likely it is the clutch cycling switch. It is the switch on top of the drier. Disconnect it and then jumper the connector. It's ok to do. That's how I test them. If the compressor comes on and it blows cold then replace the switch. It's a simple on and off repair. Very common problem. Your system may be over charged also. I would take it to a dealer or an a/c shop and have them evacuate and recharge the system. At the dealership I work at we charge about 80 bucks...

[quicksilverdon]

Listen to Slarty.
Too bad you didn't post here first - I could have told you it wasn't engine cooling fan, because you would've overheated, not just lost A/C.
I've had cars where A/C clutch went - if that ends up being it (check switch first) that's easier/cheaper than compressor.

[slartyblarfast]

I've also experienced cars that the low side of the fan will work so the car doesn't overheat but the high speed doesn't work so the a/c doesn't work very well or at all at idle. Just had one last week that did that. Never did overheat but the a/c would work intermittant at idle...

[dexadel]

Thanks for the replies on this.

The fan ended up needing replacing anyway- I think it was running, but very very slow if at all. I tapped on it with a screwdriver and about a cup load of dirt/dust came pouring out. It ran intermittantly, but stalled out again. So it was pretty much burnt out. Replaced it anyway- easy job. A/C still didn't work. Don't know why it never overheated...

I'll try jumping the cycle switch to see if that does it. I figured it was the compressor at this point since I haven't heard it come on. I didn't realize a bad switch would keep the compressor from starting up. Haven't done it yet because the cheapest compressor i've found is $260... I think i'll try the switch first.

I appreciate the help!!! I'll post in when I find out the issue in case there's similar problems out there.

[dexadel]

...and it may be the valve- but it hasn't lost refridgerant. It was full already. That was the first thing I tried. I added a can, and it spit it back out of the pressure relief valve on the bottom. Sounded like an air compressor releasing it's pressure. The guage for the coolant kit read that it was full, and it reads that still.

[bados]

I'm no mechanic, so when I had that problem I went to Chrysler. 2 visits and $1800. later...it's fixed. Here in So. Florida, on very warm and humid days I have to use the inside recyle mode or I'll roast.