My air has always worked well but the compressor always made what i call a groaning noise when it operated and I could hear this inside the truck. I have owned this truck since it was a year old. Once in a while the AC would flash on the heater control and I would disconnect the battery and reset and it would work again. Now the AC doesn't work at all and the AC flashes every time I start it up. Is this more than a recharge problem?...is it worthwhile to try to fix?...thx