a/c compressor cycling losing voltage at idle speed

[AllOriginal]

I have 89 ranger, v6, 2.9L. The a/c clutch cycles off/on about every 2 seconds at idle, as soon as engine is brought up to 1200 rpm or higher the a/c clutch engages and works normal.

I've verified I am losing voltage at the compressor each time it cycles off/on.

I put gauges on system and low and high side pressures are normal.

I replaced wide open throttle relay and throttle position sensor.

I bypassed the low pressure switch and the clutch still cycles.

Any ideas on what I should check next?

Thanks