AC stopped working after engine work

[CraigFulton]

I believe it’s electrical. I personally replaced everything on the system of this ‘76. It was working great before I had to remove the head to fix an exhaust bolt. Now I turn on AC and I don’t hear the compressor kick on. Fan runs. Anyone have any clues where I can start looking?

 

[dyeager535]

Two main ones IIRC, two wire plug to the compressor, and a pressure switch in one of the AC hard lines? Both of those connected?

A bit older system, but I assume they didn't change much...

 

[CraigFulton]

You are amazing! The pressure sensor connector was loose. All good! Whew. Hot as hell in FL today.

 

[CraigFulton]

I spoke too soon. Whatever the piece is before the pressure sensor seems to be a problem.

 

[imiceman44]

I spoke too soon. Whatever the piece is before the pressure sensor seems to be a problem.

If the refrigerant is low it will not run but will cycle so if it worked a little when you plugged it in then stopped you have a leak

 

[CraigFulton]

It’s full of coolant. The issue is the thermo whatever sensor that is inline with the pressure sensor. It’s made to detect if the lines freeze and shut it off.

 

[imiceman44]

It’s full of coolant. The issue is the thermo whatever sensor that is inline with the pressure sensor. It’s made to detect if the lines freeze and shut it off.

It freezes only when it is low, or when it reaches the temperature setting

 

[CraigFulton]

It didn’t freeze. The sensor is bad.

 

[imiceman44]

It didn’t freeze. The sensor is bad.

That will do it too