Caldina Aircon

[Technohedge]

The aircon is not functioning on the GTT. I was told this is due to a bad valve behind passengers dashboard (expansion valve location I think).

However ive noticed the compressor clutch does not seem to be engaging when i turn the aircon on via the panel switch. There seems to be a 3 pin connector and there aint any power going to it at all. So I have no idea if its the compressor/power to the compressor or what.

Are there any aircon experts in here? (i work with refrigeration systems but im not familiar with the control system on a vehicle mounted system).

muchos gracias

[Technohedge]

For a start it would be good to know what signals are on which wires to the 3 pin on the compressor. Just so i could give it some power and see if the clutch solenoid is working.

[matt dunn]

If you just want to see if the compressor clicks in,

then find the A/C Clutch relay and bridge it.
That will put power to the compressor as all the controls and switches etc are on the control side of the relay.

[edwagon]

I am not familiar with Caldinas specifically but Toyotas are known for leaks from the various AC valves - the throttling valves on the jzz and jzx are notorious, and Ive done a bit with the Surfs as well

Have you pulled out the glovebox and checked if the valve has signs of leaking?

Have you confirmed that there is refrigerant? Just hook up a set of your gauges....

You wanna be a bit careful just bridging the compressor clutch unless you've confirmed if there is pressure as the refrigerant contains the compressor lubricant - and without it the compressor will assplode if run for any length of time

Basically the compressor clutch is on the end of a set of series wired switches AND A FUSE eg: A/C Switch (obviously), Fan Blower switch (also obviously), Refrigerant pressure, evaporator temp, sometimes Engine ECU (eg: full throttle/over rpm), sometimes HVAC ecu etc

The heater resistor also usually comes into it and are a bit of a consumable

[matt dunn]

You wanna be a bit careful just bridging the compressor clutch unless you've confirmed if there is pressure as the refrigerant contains the compressor lubricant - and without it the compressor will assplode if run for any length of time

Correct, good to test it works, but only for a few seconds,
as once you know the clutch itself works ok,
there is no point running it any longer.


Also when you try to turn the AC on, do the radiator fans come on?