Volvo Repair: Volvo 850 Air Con, volvo 850, systom

Question
I've recently purchased a Volvo 850 T5 1996(N)2.3 Turbo. Only problem i have is with the air con. What happens is when i switch the air con switch on, the light does not illuminate but i can hear something trying to work under the bonnet, it only tries for about one second and then off for about 3 seconds then back on alternating, also the revs change slightly as this happens. The air con is not working at all. Any help would be greatly appreciated. Thanks

Answer
Two problems:
What you hear working, and a notice in engine speed change indicates the a/c compressor is coming on and cycling off which is normAL operation. When the ac systom is low on charge, the system will cycle on and off too fast. This will require a recharge and check for leaks.

The light being out is probably just the bulb at the switch.