Stovebolt.com Forums The Shop Area The Electrical Bay 51 3100 Ignition Switch

I've managed to screw up my ignition switch wiring big time. As you know, the 3100 switch is not marked for terminals and where they go. So I have traced everything back and here is what I have. I am ASSUMING that the two terminals on the switch are facing up and the single terminal is facing below. I have traced the following: To Coil +, to Elec Fuel Pump, to Gas Gauge, to Batt, to Ammeter + . Can someone tell me where the wires go? (assuming is have the orientation correct)

The original switch, as you know has three terminals, but only two were used. When you turn on the switch, it powers both the ignition terminal and the other terminal (maybe for accessories) and when you turn off the switch, it disconnects the power to both. You can use a multimeter to see how each terminal is powered.

I’ve included a picture of the electrical diagram for a ‘51. Keep in mind that if you converted to 12 volts the wiring will be a bit different.

I have converted to 12 volt and I do have the Diagram you attached. Just trying to figure where everything goes. Also does the switch turn off to ?the right or to the left?

Most all USA rotary on/off switches are CCW to off.

Does not matter which terminals are used on that switch as long as the hot feed is alone on one terminal. The other two are for everything else that is supposed to have "switched hot". Generally you would wire the switch per the wiring diagram. The 12V conversion has a few things different than on that diagram, as well as the electric fuel pump wiring.

Your switch works as follows. The 3 terminals have no continuity when switch off. Same 3 terminals have continuity when switch on. This can be confirmed quite easily with all wires disconnected and an ohm meter used. (continuity tester)

The Plot thickens. I have two supposedly identical switches. One tests for continuity going CCW and the other test for continuity going CW. I currently have the CCW to ON and my ammeter is constantly the hot lead so I put that on one terminal alone. Everything else got divided among the balance of the two terminals. With the ignition switch to ON, the electric pump comes on and everything seems copacetic .....except my Tach stopped working. WTH?

CCW ignition switch = Theft deterrent.
Either that or it was for a right-hand drive vehicle, operated with the left hand.

Recheck how your tach is connected. Must be something else other than the weird ignition switch.

Hmm, a good explanation why my Suburban's switch is wired "backwards"/incorrectly (for a few decades).

Remember, I said USA On/Off switches are CCW to off. That means a two position switch made for USA auto in the Stovebolt eras. Some three position switches could have accessory at CCW. I assume your switches are two position. Someone would have to show me a USA automotive two position switch with CCW as "ON" for sale.
When I said CCW to off, I meant at CCW, switch is off. 51bowtie: you said "I currently have the CCW to ON". Does that means the switch is ON when at CCW? That would be a crazy switch to use. The danger of leaving switch ON, over rides any theft deterrent.

If it's a 3 position switch with left to right positions of ACC - OFF - ON, that might explain why the tach doesn't work if it's hooked to the ignition terminal and everything else is hooked to accessory terminal. Does it run with the switch all the way CCW?

Believe Me. Both are two position switches. Weirdest thing I ever seen. CCW to Off or CW to Off, you can only get the key out in the OFF position.