I know exactly Jack **** about AC systems, but do you hear the AC Clutch - does it click on/off repeatedly trying to activate the compressor? If so, you're probably low on Freon. This diagnosis also synchs with the air being warmer or cutting in & out.
Otherwise, make sure the Clutch is working properly and check the relays. You're gonna have to whip out the Service Manual.
If you do have to go to a shop - go somewhere really reliable. You're running the older refridgerant in there and they love to sing about how $$$ it is and burn people to replace components that don't need replacing.
IF you're low on Freon - it's probably because the seals on the compressor are going. If you live somewhere cold and don't run the AC all winter, they can dry out, shrink & get brittle over the years and start to leak. There's a lubricant in the freon to lube the seals... You will notice oily film on the compressor face... You can buy rebuilt or new units - and I bet that Nippondenso makes the compressors for 4th gens. (just a guess - you should check)
Otherwise, make sure the Clutch is working properly and check the relays. You're gonna have to whip out the Service Manual.
If you do have to go to a shop - go somewhere really reliable. You're running the older refridgerant in there and they love to sing about how $$$ it is and burn people to replace components that don't need replacing.
IF you're low on Freon - it's probably because the seals on the compressor are going. If you live somewhere cold and don't run the AC all winter, they can dry out, shrink & get brittle over the years and start to leak. There's a lubricant in the freon to lube the seals... You will notice oily film on the compressor face... You can buy rebuilt or new units - and I bet that Nippondenso makes the compressors for 4th gens. (just a guess - you should check)
