We have a 20 amp 240 volt (split phase) Hotpoint Window A/C installed on our farm. The manufacturing date is 1979, but I have no other information on it. Recently when I turned it on, the fan started fine, but the compressor failed to start and was making a grinding noise, causing the power to surge. The breaker then tripped. I know about electrical and motors but know little about air conditioners. The unit only gets used a few times a year. What should I do?

It's 33 years old! A newer unit will probably pay for itself over 1-2 years due to the higher efficiency. I'd replace it.

Before I replaced it, I would check/change the compressor capacitor. Usually only run around ten bucks. However, it may be wise to put that ten bucks towards a new unit as mao641 suggested. At that age, there is a good chance the compressor is toast, and if it isn't, something else is surely soon to go.

I was wondering what would cause the grinding noise and failure to start. The only reason I'm hesitant to replace it is we only use it maybe 3 weeks (max) out of the year, otherwise we just run the fan to circulate air.

To the scrap yard it should go,, 33 years, its not worth the 10 bucks