Where can I get a replacement AC Compressor for 1977 455ci

[slshearer]

Hello

Looks like my AC compressor clch is stuck! Could be rusted due to sitting for 8 years but I did spray it down with CB Blaster and hope it frees up, Does anyone know what is the is it the same for the 1977 Tornado or is it from a Truck adapted fir the RV, RockAuto has some but not sure they would be interchangeable. Any tips on a
replacement AC Compressor and Clutch for this unit?

Thank you
Stewart

 

[RF_Burns]

Is the clutch stuck ON (compressor runs all the time) or stuck OFF (Compressor never runs)?

If it is stuck OFF (Compressor never runs) did you check for power to the compressor clutch? There is a low pressure switch that opens to prevent compressor operation if the system is low on refrigerant.

Here is a wiring diagram of the HVAC showing the low pressure switch. There is also a switch in the expansion valve that shuts down the compressor if the evaporator freezes up which could be faulty.

78_HVAC_Control

<p>Look Carefully at the colored section of the circuit diagram. The purple bar is the fingers of the function lever that will make connections on the traces of the control board. The centre red is power that is applied to the switch. The Blue is the fan Power Control going to the speed switch...

www.gmcmhphotos.com

 

[Bhart]

It is an A6 compressor used throughout GM vehicles in the 60's as well as 70's. Heavy and awkward to handle.
I use a 3/8 all thread on the bolt hole that binds the two brackets over the valve cover and hang the compressor on the all thread fastener.

 

[slshearer]

Is the clutch stuck ON (compressor runs all the time) or stuck OFF (Compressor never runs)?

If it is stuck OFF (Compressor never runs) did you check for power to the compressor clutch? There is a low pressure switch that opens to prevent compressor operation if the system is low on refrigerant.

Here is a wiring diagram of the HVAC showing the low pressure switch. There is also a switch in the expansion valve that shuts down the compressor if the evaporator freezes up which could be faulty.

78_HVAC_Control

<p>Look Carefully at the colored section of the circuit diagram. The purple bar is the fingers of the function lever that will make connections on the traces of the control board. The centre red is power that is applied to the switch. The Blue is the fan Power Control going to the speed switch...

www.gmcmhphotos.com

Hi The clutch is frozen or at least it did not turn by hand with no belt, I put CB Blaster on it yesterday see if it was rusted up, Thanks for the information
Stewart