The trinary switch is easily purchased, but it needs an appropriate fitting/port in the system high side. If you don't have that available port and only the ONE typical Hi Side fitting used in the old GM vehicles than you would need something like in the PIC I posted in my earlier reply. It would use a TEE fitting that threads on to the existing Hi Press port, then has both a service fitting for the quick connect hose fitting, as well as second port for the trinary switch.
Take a picture of this fitting (see below) on your car with the CAP REMOVED so we can see if it's an r134a port only, if it's an R12 port with an adapter added on. It's not easy to tell from that angle.
If it's the original R12 hi press port, then it could likely accept that type of a TEE fitting so you can install the trinary switch, and still have the service port for the gauges hose quick connect. You see how the port on the accumulator with the BLUE cap (lo press) has an adapter that is threaded on to the original port? That's what I'm wondering if the Hi Press port has, because if someone custom made that HOSE, they may have used a r134a fitting which isn't just an adapter you can remove and replace with a TEE. The good news is there is a nice section of straight tubing from the HOSE crimp to that existing port that could easily be cut and install a compression fitting with a port for the trinary switch to thread into.
Another option could be something like an inline (o-ring) fitting that could go in between that evaporator inlet fitting that the trinary switch could then mount to like the following.
I hate to sound repetitious but, the reality is there are so many different ways to approach/correct/repair the issues you're having with the AC system, and I highly recommend you find a local shop that specializes in AC repair. They should be able to get you going with the compressor seal repairs, and trinary (or other switch configuration) to ensure your electric fans are wired properly to come on with the AC system.
Take a picture of this fitting (see below) on your car with the CAP REMOVED so we can see if it's an r134a port only, if it's an R12 port with an adapter added on. It's not easy to tell from that angle.
If it's the original R12 hi press port, then it could likely accept that type of a TEE fitting so you can install the trinary switch, and still have the service port for the gauges hose quick connect. You see how the port on the accumulator with the BLUE cap (lo press) has an adapter that is threaded on to the original port? That's what I'm wondering if the Hi Press port has, because if someone custom made that HOSE, they may have used a r134a fitting which isn't just an adapter you can remove and replace with a TEE. The good news is there is a nice section of straight tubing from the HOSE crimp to that existing port that could easily be cut and install a compression fitting with a port for the trinary switch to thread into.
Another option could be something like an inline (o-ring) fitting that could go in between that evaporator inlet fitting that the trinary switch could then mount to like the following.
I hate to sound repetitious but, the reality is there are so many different ways to approach/correct/repair the issues you're having with the AC system, and I highly recommend you find a local shop that specializes in AC repair. They should be able to get you going with the compressor seal repairs, and trinary (or other switch configuration) to ensure your electric fans are wired properly to come on with the AC system.
