Switched Electric Choke?

Anyone put an electric choke on toggle switch instead of from ignition? I like to have control of my choke but would rather route some wire than a push-pull cable.

 

I don't see why not, but don't forget to turn it off. I haven't measured the AMP draw. I'll bet it's pretty high, Ron.

 

I'll have to think about this more. Good point.

 

Interesting. But I'd go with a manual cable. I like the certainty.

 

As I understand it, the choke is powered whenever the key is on, so the draw is not a concern. It's just powering a heating coil that opens the choke when it's fully hot. So for the open state, you need to supply power (and supply it for a while to get to fully open. it has a slow response time to match the engine warm up). No power will close the choke.

Some 70s vehicles with factory electric chokes have an additional terminal on the alternator that only produces voltage when the alternator is turning. This is for the case you get in the car, turn on the ignition and sit there for a bit playing with the radio before starting the engine. In those cases the choke will open while you're sitting there with the ignition on and the engine not running. This leads to the choke being in the wrong place when you do start the engine.

 

I think an oil pressure switch is a more common implementation of this idea than control from the alternator. This sends power to the choke any time you have oil pressure and the key is on. Jeep equipped the AMC V8s with a thermoelectric choke which, after some date, was controlled by an oil pressure switch (OPS). Holley sells an electric choke conversion kit for their carburetors, which presumes you will use their OPS when you install the choke.

Note that, for the AMC V8s, you need both the electric signal and the hot air signal to fully open the choke. IMO adding a switch on the electric signal does not do much for you in terms of purposeful control. With the switch off, you go from automatic control to something undefined. If you want a 100% electric choke, the Holley kit will probably fit a Motorcraft carburetor. NB I expect the Holley choke cover, since it's 100% electric, needs more current than the factory choke cover. Holley has an app note for their choke kit that should cover this. Thus you should probably use their OPS for this, or the Jeep switch plus a relay, if you use the Holley choke cover.

Note also that the BBD carb uses a 100% thermal choke cover that can be fitted to the Motorcraft carbs. This would do away with the electrical connection entirely. The rotation of the BBD element is backwards from the Motorcraft, so you.d need to remove the element and flip it over. I have tried this approach on my J10 with a 2100, and wasn't impressed. Currently I'm using the Dorman manual choke kit with an improved bracket that I made. Works well, but you need to remember to push the choke in.

 

I did the electric conversion on my Jeepster V6. I like it, pump the gas twice which sets the choke and gives the engine a little fuel and it fires right up and idles nicely.

 

My 304 heated choke was fed hot air from tubes that ran a few loops in the exhaust crossover cavity in the intake manifold. The air drafted from a small passage in the MC2100 base. There was no oil pressure switch. This is a 1973.

I like the oil pressure switch idea, I think. One more thing to mess with.