I have an '85 Dodge 600 that uses a thermostatic switch on the low side (big) hose next to the firewall expansion valve. I was thinking of changing to an '86-'89 hose (the earlier one is no longer available and I'm restoring the system) but the newer hose has a fitting for a pressure switch in the that area instead of a place for the capillary tube of the earlier thermastatic switch.

I'm far from being an A/C expert but know basically how systems works. These switches have the same general function, I believe, to tell the compressor when to cycle on and off. They both have two leads connecting them and both seem to be single pole, single throw switches.

If I would replace the hose that has a thermostatic switch/capillary tube with a newer hose with a pressure switch, would the system work? Or are the electronics completely different? Why did they change?

Thermostatic Switch:

Pressure Switch: