the instructions for my safety switch (mr.gasket #7872) say that wiring the switch throungh the starter solenoid would energize it on engine start up, could i connect that wire to a switched 12v source so i can energize it manually? i tried it and it seemed to work but the engine wasnt running and the pump was i was thinking the safety switch would've prevented that from happening.
thats the way it will work. if you put 12 volts to the post that is supposed to come from the starter, the pump will turn on. the intent is so the fuel pump will turn on right away when you start cranking before the oil pressure can turn it on.
will it function like it should with the switched 12v power source going to that post or should i hook it back to the starter solenoid?
I have installed several of these switches. In our cars if you wire it the way it says to then you will loose power to the coil powering the fuel pump. What I have done in the past is to use the power wire to energize a relay that powers the pump. This way the pump gets all the power it needs to operate and it doesn't put a excess load on the ignition circuit taking power away from the coil or ignition box. Just a suggestion here and a safer way to do the same job. Use the cold side of the starter solenoid for the temp power on the switch. If you forget to turn off the manual switch after startup the switch will not function the way it was designed to.
If you power the pump from a switched (key in run) source you've defeated the low oil pressure switch. I ran a wire from a switched source thru a push button on the dash to the pump. That way I can turn the key on and use the button to fill the carb bowls but the low oil switch will kill the pump if no oil pressure (when the button isn't pushed). I also ran a wire from the output side of the starter solenoid to the safety sw so the pump runs when the starter is running but oil pressure hasn't built up yet.
