In the clear light of morning I remembered something to add. The AC, powersteering and alternator are all mounted with rubber bushings. I believe your model will have 11 of them. Over time, these soften and the tension of the v-belts will pull the AC, etc slightly out of line inward. This makes the v-belts to be out of alignment with their pulleys. As a result the belts get noisy and will wear out faster. New belts may be quiet for awhile but will not last. The front area of the engine gets very noisy, kinda squealy type noise. You can see this by sighting down along each pulley and belt.

I've replaced these rubber bushings in several of my Volvos and things do get quieter. On my '86 240 I replaced all 11 bushings, v-belt, and timing belt recently. On my "new" 940 I did the bushings, seals, timing belt, and v-belts last week. It's a fair amount of work but not technically hard (except maybe for the seals).