AC not turning the compressor on

[rvance]

i have a 1985 3607 that the front a/c wont turn on the compressor. The light comes on like it should but compressor won't.
The heater works fine as I can hear the relay kicking in. Thanks

[g36]

What brand ac? Has it been working? Is the water pump coming on? Fan? The clicking you hear may be the reversing valve. It could be low on gas. If it ran high head pressure and has a safety for the compressor it might have tripped. May have a reset located near compressor that is a pressure switch to push. may be start capacitor.

[rvance]

It is the original ac and it did work until this year. Good water flow and fan works fine. The light works like it is kicking the compressor on but nothing.

I wasn't sure if there were capacitors on them. I did look but didn't see anything familiar.

[tomschauer]

The older vintage units have manual high pressure and sometimes low pressure resets. Look for a cylindrical plastic piece about 2 1/2 " long and 1" diameter with two wires attached to the copper pipes. Should have a button on the end, push it in, if you hear it click, it was tripped.

[tomschauer]

If it is a start capacitor, you will see your amp gauge spike pretty high for a few seconds when the stat call for the compressor to start before it locks out on thermal overload.

[buster53]

Sounds like what happened to us some years ago with our 3807. The reversing switch went bad. Our AC guy said it was an expensive repair and due to the age of the unit, didn't make sense to fix. After some discussion, we had him manually put the valve in the cooling position as we rarely used the heat setting. Worked just fine and saved us a bunch of money not fixing the switch or replacing the unit.