AC Principles of Operation

[truckster]

I'm installing the components from a 98 Silverado in my 72 Blazer with a 5.7 Vortec. I'm using the serpentine belt from 98 as well as all the components for the AC. I want to make sure I'm wiring it right. If I understand correctly, one side of the compressor clutch harness goes to ground. The positive side runs from the relay (via the AC switch) through the low pressure switch as well as through a cycling switch and then to the other side of the clutch harness. One switch is on the accumulator and the other is mounted on the manifold at the rear of the compressor. Is this right?

Thanks in advance.

[speedygonzales]

You left out one critical component. The PCM

All the switches you listed are hooked to the PCM. The main reason is so the PCM can raise the idle when the compressor kicks in.

The high pressure cutout switch comes from the on/off switch then goes to the PCM

As far as the cycling switch and the low pressure cutout. They are grounded on one side and go directly to the PCM on the other.

NONE of the switches are inline to the compressor. There is a clamping diode across the inputs to the compressor clutch.

The compressor relay under hood is obviously controlled by a PCM output.