AC Compressor Not Turning On
Ive got an 06 Elise which I am going to be selling for a friend and I'm helping prepare it for sale. During inspection I noticed the AC was not working. When the car is running with the blower fans on, temperature set to cold, and the AC button pressed (it turns blue when pressed) the compressor does not turn on (I looked in the back). Here are the steps I have tried so far to fix the issue.
1) Checked all of the fuses for the AC system (both in the front and by the passenger footwell) all are good.
2) Figured the lower pressure switch was triggered in the AC system so I had the system evacuated and recharged. Still won't turn on compressor
3) I opened up the AC control module (the relay pack located in the front under the service panel on the passenger side). Checked the input voltages and they are good to go. When I turn on the AC inside the car, the AC control relay doesn't close... When I start the car and manually close the relay the compressor turns on and the air gets cold, yay! So I have tracked it down to ECU Pin 53 not pulling to ground when the AC button is pressed.
Anyone have an idea why the ECU would not engage the AC even when the blower motor is running and the AC button is pressed and the blue light comes on?
If we are going to run out of fuel, might as well have fun doing it! ~My Father