One of the wires coming off the switch (red w/white stripe), should connect to the choke. The other is for the manifold heater.
Again, gong on memory, here, so someone please correct me, if I'm wrong.
Matt
Actually close but no cigar.
One wire is power coming from the back up light circuit. The other wire goes to a relay for the manifold heater AND the electric choke on the carb.
or in more detail:
Or picture wise:
I think this is the relay socket one of those red wire runs to.
Check here to see if the wire from the switch runs to this relay socket.
Usually though the wire to the E-choke runs through a 6 terminal plug which is usually removed in a nutter hack so you might not have the wire that runs to the e-choke. You might not have the 6 terminal connector anymore. If you do, that's good, just splice in a wire with the correct socket and plug it into your e-choe terminal.
Se my picture up above to what each connection looks like.
Get your test light out and see if you have power to one of the terminals on the oil pressure switch. then start the engine and make sure you have power to BOTH terminals on the oil pressure switch. If your backup lights work, chanses are this e-choke circuit also should work.
If you are not going to run the manifold heater then you just need to run one wire from the switch to e choke terminal.
If you want to hook up the manifold heater then we can address that later.
Usually though I adjust the choke by loosening the e-choke housing.
1. I lay a brick or something on the accelerator pedal to keep the carb throttle open fully.
2. Adjust the housing so it just closes the choke butterfly.
3. remove brick and start engine
4. Adjust idle speed for cold engine and then for warm engine
Not sure of the adjustment on a 2100 though. I'm sure you can find a ton of info on how to adjust the choke and idle on a 2100.