Mysterious Belt

1989 Saab 900 4 cyl turbo:

Just got this car. There is a rubber belt that shares the pulley on the alternator. It is a toothed belt with the teeth on the outside as it wraps around the alternator pulley. It disappears under the ac condensor and then I can't see where it goes from there. It is very loose and very badly worn.

I have not yet located a good manual for this car and was wondering if anyone knows what this belt does.

Thanks.

I think that's the one that goes to the water pump. The teeth should be on the inside!

lol... that certainly is an interesting problem...