Avanti AC Rheostat

[Avanti82]

The AC quit working on our 82 and I took it back to the shop that did the R34 conversion for us. I did not want to leave the car the day I was in but the mechanic did a quick check and said the compressor was not getting any power from the rheostat, the compressor would not come on at any setting.

If in case the rheostat is the problem what are the options to fix or replace it. Is this a common problem on the Avanti system?

Thanks
Steve

[Rerun]

Steve,

There are actually two switches involved. First, there is the Off/On and fan speed control switch. When this switch is turned on, with the fan rheostat at any speed, power is furnished to the thermostat switch that actually turns the compressor on and off.

If the fan doesn't work, check the fuse. If your fan works, but not the compressor, you know that there is power there, and the fuse is not blown.

If you remove the panel that holds the switches, you can do some basic checks with a volt meter. Remove the panel screws, unhook the bottom, and carefully pull the panel out. There is a temperature sensing tube from the thermostat switch that is stuck into the evaporator coils. It is flexible, but be careful not to kink it.

When the fan is running, there should be voltage on the rheostat terminal that is wired to the thermostat switch. If you set the thermostat switch in the coldest position, there should be voltage on the terminal that goes out to the compressor. The operation of the thermostat switch can be checked by dipping the end of the tube alternately into warm water and ice water. You should be able to see the contacts moving in the switch, and hear the switch clicking.

On some systems, there is also a Freon pressure switch (under the hood) that will not allow the compressor to run if the charge is too low/high. I don't know if they used one on the '82. My '78 doesn't have one.

All that said, if either your rheostat switch or your thermostat switch is bad, you should be able to get either one (generic) from your local A/C shop. OEM parts may be available through the normal Studebaker parts vendors, too.

Hope this helps.



Jim Bradley
Lewistown PA
'78 Avanti II

[Avanti82]

Jim, this helps a lot, thank you. The fan is working normally so I can focus on the other components for the problem.

Steve