[Wgesnerjr]

Just some thoughts:
The idea is that the electric choke heats up when it gets 12v. There is coil spring in the housing that changes shape as it heats up and moves the choke from closed to open. So there is a certain length of time that it takes for this happen and by the end, the engine should up to temp and no further choke needed.

However from the factory, the electric choke was wired from an ignition circuit through an oil pressure switch to the electric choke.

Why an oil pressure switch? The switch closes when there is oil pressure (engine is running) and lets the current through to the choke.

Having the switch, prevents the choke to heat in case the driver turns the key on but does not start the engine. In this situation the choke would heat up and open well before the engine is started or up to temp thereby making it hard to eventually start or run the engine.

So the switch would ONLY let the choke heat up when the engine is running.

If you plan on running an electric choke without the switch, you have to always remember to turn key and start engine. Don't let the key sit in the ON position without the engine running.