A/C cutting on and off

#1 04-16-2004, 03:50 PM

Hi,

The shop finally got my A/C to work. However, earlier today it cut on and off a few times when I first started it up. I had the shop add some flourescent leak detector to the freon, in case it leaks again. The second time I got it back from the shop it would run but I could see lots of foam in the sight glass. Now the sight glass looks green inside (I'm assuming that this is the dye!) but I can see no bubbles or foam. After it gets running for a while and quits hiccuping the canister-looking thing going into the compressor is rather cold, so I'm assuming that there is at least enough freon in there; is it possible that there's too much? I think the high side was at 130 or 150 psi at 50 degrees when tested, but I could be off on those figures.

Thanks,

ensteele · #2 04-16-2004, 05:38 PM

Yes, it is possible to have too much in it, but I would take it back to the place that did the work for you, and have them check it.

#3 04-16-2004, 11:50 PM

Well, I did the A/C diagnostics and I get a code 14 (evaporator sensor). This code is intermittent. I know that this a resistance/temperature sensor for the evaporator, but what purpose does it really serve? If this thing has gone bad, can I just put in a resistor between the wiring connector leads to make it work? How does the car know that the sensor is not reading the proper resistance anyway?

lee · #4 04-17-2004, 11:54 AM

I don't know the exact nature of the resistor (probably actually a NTC thermistor) in the circuit, but I'm guessing it has to do with the duty cycle of the compressor, i.e., cold evaporator, turn down the compressor and vice versus.

The data I have on the system shows the code comes up for a shorted or open circuit. If you have a VOM and are willing to run a few tests, I can post the text, or you can download direct from reaper's site (which is where I got it from).

#5 04-17-2004, 01:37 PM

Yeah, I've got it saved on my computer from when I was trying to diagnose it earlier : ) I'm just wondering, has anyone else out there had a code 14, and if so how did you fix it? The document states that it's an open circuit; that implies that something's perhaps not fully hooked up. Just wondering what most likely needs replacing...