Air Conditioning Problem

When I bought my Jimny part of the air con had been stripped out to make way for a winch. I've now reinstalled the missing bits and gassed up the system but it won't work. If you feed power to the compressor it will lock in and the system will get cold.
The push button light on the dash will go green if you hold it in, but not if you just latch it in the normal way, but the system still won't work. The car was a push button transfer box type, but now has a Rockwatt so there are several connectors hanging around by the transfer box.
The question is please, is there a connection between the transfer box and the air con ie when you select 4wd or low range, does it turn the air con off. I have disconnected the wiring to the 4wd controller because all the 4wd and low range lights were on all the time, so the car thinks its in low range regardless of what it actually is as it has a Samurai transfer box. To complicate matters even more, with Martin's very able assistance, I have now got the the 4wd light on the dash to operate when you select 4wd, but only by cutting a wire from the 4wd controller and connecting it to the transfer box. The wiring diagram would seem to suggest that there is a connection between the air con and 4wd controller but if someone who has an original push button car with air con could confirm or otherwise if the air con does turn off in 4wd that would be a great help
Are you still with me!!??

The aircon is disabled in 4WD according to the circuit diagrams and the workshop manual. It appears to be in the same circuit as the aircon overpressure switch.

Martin

That's great Martin thankyou - do you know how I can fool the 4wd module into thinking its in 2wd? At the minute all the lights are on as if its in low range. I imagine its necessary to connect 2 of the wires that would have gone to the original transfer box.

I had to compare an old manual car with an electronic one.

1. An old "manual" car only has a 4WD controller. The transfer box is put into 4WD using the lever, therefore the controller has to detect this and engage the vacuum, thats its only job apart from deciding that certain conditions are wrong and therefore it should refuse to engage the vacuum.

The old controller has 10 connections:

1: Vacuum control valve (output)
2: Vacuum control valve (output)
3. 4WD Light and ABS Controller (this must be an "output")
4. ECU (?)
5. Ground
6. Vacuum sensor switch (input)
7. 4WD Transfer box switch (input)
8. A/C Pressure switch (??)
9. Tacho
10. Power (input)

Therefore the only real inputs on the old controller are 6,7

2. A new electronic car has the 4WD controller and a transfer box controller. The transfer box controller looks at waht buttons you have pushed and controllers the electric motors that drive the transfer box. Using sensors and switches on the transfer box it then decides if you have been successful in your selection and then tells the 4WD controller to engage the vacuum. Therefore it then switches connection 7 on the 4WD controller to earth to signal it to switch the vaccum.

However there is the connection from the 4WD controller to the A/C, but its unclear wether the 4WD tells the A/C that 4WD is on or whether the A/C tells the 4WD that it is on? And both have connections to the ECU. The ECU seems to have master control of the A/C as it controls through relays the compressor and condensor. You should be able to force the the A/C by grounding these connections.

Out of interest I had a look, It appears that you need to remove yellow connector E74 from the 4wd controller, located at the right hand side under the dash and join the green/black to green/white.

While you are messing with e74, I reckon joining blue to blue/black will make the 4wd light come on properly if the transfer box switch is connected, or at least earthing the blue wire will light it up.

Martin and Facade - thank you very much for your help. I am setting off to France today with it (on a trailer!) so won't be able to play with it for a couple of days but will let you know what happens. It would be really good to get it working. Just hope I don't damage the ECU!