A/C coolant Temp switch - Location (2 Viewers)

[Richard Luksozek]

Fantastic. makes 100% good sense so just need to do my bit before I can test it. Thanks for the pic, yes its exactly what my Troopie has. Thanks for the tip on the O rings. The guy who gassed the system made the same comment that over time I might find a tiny leak develop from drying O-rings. I think we have just about nailed this problem. Once I find the Black/Blue wire then will make a comment to close the thread. Thanks so much everyone.

 

[prwillard2]

Mine is colocated with the fan dial.

View attachment 3608437

You showing this helped me fix my own AC. Thank you @Houser

For @Richard Luksozek did you change out your switch? I also added heat to mine and the heater controls didn't come with the amplifyer nob.

My clutch wouldn't engage with the euro model switch, I had to put the GCC nob into my other HVAC controls.

You can see from the last pic, the GCC nob & A/C slider uses all 8 pins in the plug. The Euro model switch only uses 6.

 

[Richard Luksozek]

Thanks @prwillard2, yes that pretty much sums it all up and yes that's my setup as well. Dual function control. The Fan controller in the circuit diagram is very vague in that it doesn't spell out the internals of the Fan combination sw. The two parts, however, are the four positions that control the fan and must be in one of these positions for the A/C clutch to pull in and the temperature thermostat. That is the mystery yet to be tested and what @Engineer8000 suggests controls the heating by way of engaging and disengaging the clutch which is set by the thermostat control. Makes sense so will testing as well. The Thermostat has two yellow wires that go to the Amplifier (two of the 8 pins as you suggested).

 

[jblueridge]

Just out of curiosity, what refrigerant is in your system?
I have outlawed R12 freon.

 

[Richard Luksozek]

Just out of curiosity, what refrigerant is in your system?
I have outlawed R12 freon.

Here in Aus the most predominant gas used for all A/C systems (auto and domestic) is R132 I think. At least everyone I've spoken to all refer to R132.

 

[HZJ75 FARMER]

Here in Aus the most predominant gas used for all A/C systems (auto and domestic) is R132 I think. At least everyone I've spoken to all refer to R132.

Do you mean R134a?

R134a is the most common refrigerant in mobile airconditioner systems in Australia.

 

[Richard Luksozek]

Well have traced the wire from the Amplifier that operated the clutch via the A/C Coolant Temp Switch. (Located half was down the intake side of the 1HZ block.) Wire from Amplifier is Black then changes to Black/Blue (see diagram above) where it then connects to the switch (no longer there on the 4JJ motor). The other wire on the plug is white (N on diagram) and it seems Toyota use White for Ground/earth/Neg. Tested it with my meter and sure enough it has a circuit to the chassis. So just bridged it together and like magic clutch pulls in. Next was test the Thermostat on the Fan combo switch and sure enough rotate the inner temp knob to minimum and clutch drops out as @Engineer8000 suspected then rotated upwards engages the clutch again. Well I think that closes this thread. Again thanks everyone for all your input. Great result.