A/C acting weird

[kelsie180sx]

Hi! Kelsie here,I have a 1991 nissan 240sx. When the car first starts the A/C works fine and the light stays on. But the weird thing about it is once I go over 30 mph the A/C goes off and the A/C light flashes. And when the light flashes the rpm revs up and down. Did anyone hear such thing??

Thanks

[JT_MONEY_2004]

Sorry I've never, and seems like no one on this board has either. Take it in to a nissan specialist.

[navysnail]

thanks for "bumping" this JT, accually, i have some idea

ok, for the 30mph thing, let me think about it

the idle going up and down, is caused by the accv (it may be a different one, dont know off the top of my head) anyways, what this does is allows more air into the motor when the a/c is on to compensate for the added strain of turning the compressor.

the system may be low, check behind and below the passanger headlight, you will see a silver canister with a small glass window in it. clean off the sight glass run the car and a/c, and look into it, if there is bubbles or it lookes like fog, then it is low