[motorheadchuck]

I need to get a hold of a thermal cycling switch for a 77 t/a. Its the switch mounted on the engine side of the A/C box. I dont know exactly what it does, but I need it. Also, am I able to just jumper around that switch or is that going to damage something. Please let me know ASAP if anyone can help me with this.

[Squidward]

With it jumpered, your compressor would run continuously, even in low load situations. It could get you by for a while, but the compressor would continue to run even if the evap temp drops below freezing. This could cause condensation to freeze up and plug the airflow thru the evap.

Try contacting ACKITS.COM. They may be able to find you a thermal switch from another application that would work.

If the system is currently vented, you might consider getting an 80-81 accumulator that has a pressure switch port. The accumulator and cycling switch are available from Autozone. This would elimate the need for a thermal cycling switch. That's a possible option if strict originality is not an issue.

[Squidward]

BTW, the switch cycles the compressor on and off based on the temperature of the evaporator. It tries to keep the evap temp from dropping below freezing temp during low load. 77 & 78 used thermal cycling switches to cycle the compressor, 79 (?), 80, 81 used a cycling pressure switch on the accumulator to accomplish the same thing. Most cars built today use the cycling pressure switch, since it has proven to be cheap and reliable.

[allenga]

Originally Posted by Squidward

BTW, the switch cycles the compressor on and off based on the temperature of the evaporator. It tries to keep the evap temp from dropping below freezing temp during low load. 77 & 78 used thermal cycling switches to cycle the compressor, 79 (?), 80, 81 used a cycling pressure switch on the accumulator to accomplish the same thing. Most cars built today use the cycling pressure switch, since it has proven to be cheap and reliable.

Sir do you know where to get the black crud used to hold the capillary tube to the evap pipe..

[Bentwheelbob]

Originally Posted by allenga

Sir do you know where to get the black crud used to hold the capillary tube to the evap pipe..

https://www.classicautoair.com/shop/refrigerant-tape/

[allenga]

Thanks Bob. I do use that tape to insulate the evap pipe coming out of case.

On my original car, they did not use this tape for the capillary tube.

[Bentwheelbob]

Do you have a picture? I’m not sure what a capillary tube is.

[allenga]

Originally Posted by Bentwheelbob

Do you have a picture? I’m not sure what a capillary tube is.

I am going to replace this switch.

[Bentwheelbob]

3M Strip-Calk.

https://www.amazon.com/3M-08578-Blac...r=8-1-fkmrnull