Vintage Air Binary to Trinary and..??

[epfatboy]

I have a '74 C10 running a typical standalone harness to a P59.
Went to pull a wire to the harness and discovered I have a binary pressure switch... which is great until you remove the fixed fan and replace it with cool electric fans.

Now I need a Trinary to run the fan relays..

I have been running the truck this way for a little bit not realizing this, the driving mostly cruising with little stop and go.

Gonna order the parts now, should I put her up until this is repaired?

Also.. the original idea was to run 12v when the compressor came on. Which means I still need to pull from that side of the pressure switch ... right?

I believe the fan side works on a different pressure so the fans don't cycle with the compressor which isn't the feed the PCM is looking for.

Is that accurate?