330hp_91RS

Here's the deal....just bought a 1995 Trans Am. Car was sitting for over 1 year, it was driven 700 miles last year.

The A/C does not blow very cold, so I got the little Wal MArt setup and tried to boost it up a little.

Now the compressor won't come on. It says in my manual that the charge may produce low pressure which in turn makes the clutch on the compressor release even when the A/C is on.

Most R134a systems have a sensor in the accumulator/ receiver-dryer that has two prongs and you can jump to get the compressor to come on.

The only sensor I can find is on the HIGH side right by the nipple fitting to add fluid on the LOW side. The sensor is located on the line right beneath the fatter line with the nipple.

So this sensor has 3 terminals...What gives? When I jump it, the compressor still does not come on. When I jump 2 of them, I think the Black wire and the Gray wire, the car shuts off. PCM shorting??? Now today I tried jumping the A/C realy and the compressor came on and the air started blowing cold, or kind of cold at least.

I tested the pressure and it came out to be 45-50 psi. The temperature where I live is 105-112 degrees, so according to the chart, that pressure reading id about right.

Any ideas why the compressor does not come on??? I checked the wiring diagrams for the car and there are not anymore sensors, just the one with 3 wires/terminals.

I guess that this system replaces the high pressure and low pressure switches with one sensor.

Dave Y

that sensor is a pressure transducer, the PCM controls the A/C on these cars, so, if you have access to a scan tool, see if the A/C pressure reading in the PCM is out of whack(i.e., if it reads 255psi ,the pcm will NOT turn thr A/C on)