The Air conditioning on my '95 D-2500 likes to work off and on, works great when it does, and when it doesn't the compressor isn't running... It can work for anywhere from a few minutes to several hours at a time, same with the off status... I've rotated the relays and then replaced the A/C one with a new one, checked the charge with a set of gauges (seemed a bit high but I don't think that's it), the belt is brand-new and tight (I mean the compressor isn't clicking ON when it's not working), wiggled a few plugs and this and that, any ideas as to what it could be?

 

check the refrigerant pressure switch?

 

I know I'm going to have to check out my AC this year as well. My AC works great when you first turn it on, it's when you start to crank it down that weird things start happening.

When you turn it down to low fan speed and turn it away from the coldest setting a bit, it seems like something freezes up and it won't blow cold again until whatever it was that froze up thaws out. It's weird !! I was told to check the AC "drain line" but I have no clue where that is. Do any of you ?

Thanks !!

Any other ideas?