The A/C stopped working properly in my 1980 280ZX, manufactured May / 80. I swapped a set of vacuum lines under the dash and now it comes on, but it will go off, with NO air flow, then come back on again full force intermittently. Also, the auto temp doesn't really work anymore in this setting. You set it to full A/C or heat. In addition, and PRIOR to this problem, the "recirc" stopped working. Pressing the button does not evoke any change in the air flow. Any help????