1985 300CD A/C Clutch

[carock]

Finally! The 1985 300CD California tachometer is working after hot wiring the EGR computer connector. The A/C clutch is engaging and disengaging every 3 seconds. Anybody know how to troubleshoot that? Nothing I do with the Klima control knobs/buttons seems to make a difference.

[carock]

The above statement is partially false, If I turn the Klima dash controls to "off" or "A/C Econ" the A/C clutch will not engage.

[carock]

The rapid A/C compressor clutch engage/disengage seems to be related to idle speed. As soon as the engine is brought up to about 800 rpm the clutch cycling stops.