I don't do any repair on a car I'm considering buying. If it doesn't work when I drive up, I price as if it needs to be replaced. I'd never try to sell a vehicle with non-working AC if it only needed a belt. Consider it as compressor replacement & recharge at the minimum. It may need more or less. Let the current owner fix it if it is so minor a problem. What else is inoperable?

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.