First off, I should introduce myself and my car. My name is Trey and I run a small European restoration shop in my spare time. While well versed in the likes of Jaguar, Mg, Triumph, BMW and vintage Porsche, the Volvo is somewhat new to me.

So I bought one to replace my work truck for my "day job (hi-fi)." I am very pleased thusfar with my very well maintained 88 740 GLE--white w/ red interior. The FAQ on these cars has made a huge difference in her running, as things like the flame trap issues are quite foreign to the unexpecting. Kudos to brickboard!

Anyway, back to my wacky A/C. . .

I have the basic manual control pack on this car and I understood from the FAQ that I should have some sort of AC control box integrated with the controls. This was to house a relay and some connections to the wiring harness that could require re-soldering.

Well, this is not what I have found. Seems I have a switch with wires that appear to be supply voltage+the three speed outputs+clutch control (orange/wht?). some of these are also found terminating (at least by color and guage) at the resistor pack. There is one large, green electronic relay that I assume to be the delay relay for the fan or compressor. This I have checked and seems pristene.

Symptoms:

1) Switch usually does not control fan speed at all. Often it will come on full blast with ignition but may cut off after starting the motor or at random. Once out it stays out until next re-start (usually). Other times, it stays on full blast regardless of the mode setting.

2) If the speed control switch is going to allow me control of the fan speed--which it does on rare occasion--position "0" sees the fan running everso slightly (less air than on "1") and the compressor does not shut off

3) Sometimes, if the fan is out completely, setting the switch to "0" will produce the same paltry airflow mentioned above.

My guess is a bad switch but the inference to a control unit between the switch and fan resistor pack has me concerned that I might be replacing parts willy-nilly.

Any advice is appreciated.