Ac Turns Off When Steering

[chamilka]

I have a nissan B14 car 1995 automatic. Recently replaced the alternator with a recondition one. Now in idle speed with the AC on when I turn the steering wheel AC compressor turns off. When the steering is kept in one position (wheels turned or straight) compressor starts back. Power steering and water pump is driven by one belt and AC and Alternator by the other belt. When AC is off and steering is turned engine idles up so it may not be a pressure switch problem. I suspect whether it is the belt that drive AC and Alternator because that is the only section disassembled for the repair. Could the belt be too tight and cause this? I am very much grateful for your suggestions.

[terrabytetango]

Your A/C idle is set at it's lowest. The power steering pump causes the engine idle to go lower when it is in use, which in this case is below the minimum operational threshold of the compressor, which is why it cuts out when the wheels are turned (power steering is circuit is pressurized) and cuts in when they're straight (power steering circuit at nominal pressure). Adjust the A/C idle to a higher RPM. It's also prudent to have the A/C belt examined as well.

The actual reason for for the A/C cutting in and out is not RPM based, but pressure based; the compressor will cut out if pressure is lower than the preset amount, this is to prevent the compressor from running without lube. Under normal conditions this would be because the system needs to be repressurized, but in your case the idle speed causes the pressure to drop down far enough to trip the compressor cut out.

Edited December 3, 2012 by terrabytetango