Quick dealer/warranty/busted aircon question

[Max Factor]

If I bought a s/h car from an independent dealer, and that car was advertised as having air-conditioning but I failed to check it before purchase, and the aircon expired on the way home, is the dealer obliged to fix/pay for the aircon to be repaired?

He did mention a warranty but there's nothing about it in writing. The dealer is several hours drive away so taking it back to be fixed isn't a practical option (he doesn't have aircon facilities anyway), neither can I prove that it's failed.

Just one of those things?