GM computer controlled A/C in my '48 question

[48builder]

I just got my A/C unit for my '48. It's called the Hypercool II from Northern Kentucky Street Rods. Looks like a nice unit. It's the size I wanted and I like the size and shape of the control panel. Here's my question.

I want to keep the A/C clutch under the control of my Powertrain Control Module (PCM). The PCM uses three inputs for A/C. One is the A/C request signal, one is a signal from the pressure switch located in the coolant line(which I have from my donor), and the third is a signal from the evaporator temp sensor, which I don't have.

My new unit has a sliding thermostat, with one wire coming from the selector switch, and the other going to the A/C clutch. My thought is to use this wire as the A/C request signal to the PCM. Can I also use it as the temp. sensor signal? I assume that the thermostat on my control panel just shuts off the signal to the compressor if the evaporator freezes. The A/C clutch is either on or off, so I'm not really sure what purpose the sliding control serves on the control panel.

Or, should I put a jumper on the mode select switch to use as the A/C request signal and then use the wire from the thermostat as the evaporator temp sensor?

I can also just get a GM evap temp sensor and put it in my evaporator if that's the best way to go.

Any ideas?

Thanks

Walt

[enjenjo]

The slide control sets the AC thermostatic switch temperature. If you have heat, it also controls the heater control valve. On the output side of that switch, the side that goes to the compressor, you should be ablet to connect for AC demand. I would install the evaporator temp sensor for that output.

[48builder]

. I would install the evaporator temp sensor for that output.



If I use the factory sensor, I'll be sure I have the right signal. Better that than take a chance on screwing up the PCM.

Thanks, enjenjo.