microswitch... which is terminal 30b?

[derek murray]

I'm doing the mfi check, measure, and adjust, but I am not sure which microswitch terminal is "30b". There are no visible markings on the switch and the Haynes electrical schematic does not show anything.

Although connecting to either terminal yields no results, I just want to make sure I'm doing the procedure correctly.

[jeff m]

Facing the micro switch (from left of car) the terminal to the rear of the car should give 12v+ when you increase the rpm above 1,500
That will prove your speed switch is ok.

Now test on the other terminal.
Raise rpm and release, the micro switch will operate on return of the rack and there should be 12v+ until the rpm drop back to idle.

This 12v+ will operate the fuel shut off sol. (it shuts off fuel on overun)
Jeff
911T

[Early_S_Man]

Derek,

Terminal 30b is the wire from terminal #1 of the Speed Switch ... i.e., the switched +14 Volt power that is supposed to come on above 1500 rpm, and go off at 1300 rpm. The 'other' side of the microswitch from the wire going to the stop magnet/cutoff solenoid.

An analog or digital Voltmeter works just as well as a test lamp for monitoring the Speed Switch output ... at terminal 30b of the microswitch.