[mattdavis11]

Glen, all the connections are sealed by o-rings. The factory didn't invent them and they are cheap.

Any a/c shop should be able to incorporate a tee into the liquid line to allow for a pressure switch. 7/16 or 3/8ths thread for a female pressure switch is your best bet for testing. Your accumulator has a schrader valve for the LPCO, it would be the same.

If you decide to go that route, I'd place the T on the liquid line just after the union from the condenser. If you choose to adapt an external thermo fan controller, anywhere near that union or in the condenser fins would suffice. Wrap it if you put it on the line.

I don't think you should be having this problem with an R12 system though. Having admitted that your vent temps are 40 degrees with an axillary fan tells me four things, 1) the compressor is weak (hope it's not a compressor works), 2) too much oil in the system, 3) bad fan clutch, 4) external fins on condenser won't allow air flow.

Your system should blow in the 20's all day long.

Another in line filter (orifice tube is one) just creates another possible restriction, but if you insist, I have one for an R4 that mates to the back of the compressor before the hose assembly.

Edit: five things, 5) overcharged.