Corolla 99 A/C light blinking

[nipat28]

I got my A/C light blinking.. When I start my car and turn on A/C...I heard compressor making some wierd noise for 4-5 seconds (COLD air come out), then shut down itself (WARM air come out) and A/C light keep blinking. I read many articles... Maybe A/C MG relay...I tried swap this relay with other same relays in fuse box but no luck..I am sure that refrigirant level is in good level. Now I keep bumping A/C button to get COLD air in my car.

Anyone has idea and experience to fix this problem...

[fishexpo101]

Could be a number of things. Magnetic clutch relay is the first culprit - if that doesn't fix it, double check the refrigerant charge. That should be done on both the high pressure and low pressure side, not with the pressure gauge on a DIY kit - as those are not always accurate.

Swapping with a new relay is preferred, as you limit possible issues. Try taking the relay and tapping it against a wood block or similar - sometimes a good tap will "fix" the relay.

If those check out fine - could be an ECM issue (thinks the A/C clutch and engine are running a different speeds) or the compressor is shot. The funny noises that come on when you first start the A/C is what concerns me. It is due to a bad relay, bad magnet clutch, too much/too little refrigerant, or bad compressor - can't tell until you try and narrow the culprits down with some diagnostic work.