I've searched the forum without success to see if anyone else has experienced the same problem. My '99 4.5L has the automatic air conditioning unit fitted and the control appears to be working perfectly (temperature contol, fan settings, auto/maual, etc all working fine). However, in recent times I've noticed that even when you switch the aircon off the compressor and fans continue to run. Only after I've switched the ignition off did they shut down and then stay off after I restarted.

More recently, Ive noticed that about 30 seconds after starting that both the compressor and the fans kicked in (2 different relays) and then run continously despite the fact that the control unit is switched off. As of yesterday, the moment I switch the ignition on the cooling fans now come on and I assume the relay for the compressor probably also energises. In desperation I've pulled both relays for the moment until I find the problem.

At the moment I'm working on the assumption that the automatic control box is not the problem because all indications are that it functions correctly, and that the problem may be a second relay or switching device that takes instruction from the control unit to switch the two relays in question. Can anyone help me on where to look (I cannot see anything obvious on the wiring diagram).