Electric choke hookup question

I need need to hook up my electric chokes to a "keyed" electical source. My starter selenoid is in the trunk and if I can avoid it I don't want to run it to my key switch. Is their any reason I cannot or should not hook it up to the + side of my coil? I am not a electronic guru by any means and I dont want to mess anything up. Thanks, Todd

 

Yes dont hook to your coil. Most coils only have 9 volts to them and it will take too much power out of that circuit. If you dont have a one wire alt then I believe you can hook to the stator side of the alternator and then it will only have power when car is running and that is what you want.

 

I have a "SI" 3 wire alternator. Good idea!!! Never would have thought of that. I am running a Pertronix coil. I never have checked the input voltage not sure what it is. Todd

 

Anyone else??

 

I was planning on going to the accessory side of the ignition.

 

I rigged mine off the ign. side of my 3 wire alternator, works fine.

 

GM powered the choke off the #1 terminal on the 10SI from the factory, but they used the alternator wire to operate a relay that in turn operated the choke. The only downside to this is that if you lose the fan belt, you can run on the battery but without the alternator turning the choke coil will cool off and close.

I just put an electric choke on my 62 Olds and I used a Vega oil pressure switch (Standard P/N PS64 - about $10 from RockAuto). This sender has three terminals. The one in the center is for the oil idiot light, the other two are a normally open switch that closes with oil pressure. I ran a fused wire from the BATT terminal on the alternator to the sender, then from the other sender terminal to the choke. Real easy and works fine.

 

I tapped into the windshield wiper hot wire, it's only hot with the key on, and it is close to the carb.

 

In a pinch one time I ran a heavy wire from the coil to the electric fan just to get home. I got distracted and never got it fixed properly and ended up running the car about 5 years that way. I never had a problem with it. That was a 85 Reliant in about '90. Of course that's no reason for you to do it wrong. I'd just run it to the switch or take a meter to it and find ahot wite near by.

 

joe p has the right idea, use the oil pressure switch, that way the choke will only heat while the engine has oil press., if you turn the key on it wont heat the choke premature, i have used that for years

 

Fords used stator voltage which is about 9 volts IIRC. Chevys mostly used a full 12 volts.
The one on my Holley is on 12 volts and it opens too fast so 9 volts might be better.

 

The choke is designed to operate on 12v (actually, 13.8 or so). Adjust the opening rate by rotating the plastic coil cover in the choke housing, not by changing the voltage. Again, the GM factory wiring used the #1 terminal on the 10SI to close a relay. The relay switched battery voltage to the choke coil.