Power for electric choke

[jscott]

My 351c H code has a Holly 4bbl (unknown model) on it.  It has an electric choke and the wire for it runs into the cabin and was rigged to one of the fuses.    Is it ok for this to have constant power?   Where would the power normally come from for an electric choke?  Seems silly to have a loose wire running thru the firewall to the fuse box for this.

 

[TommyK]

The electric choke should not have constant power. It needs a switched power source. Many people run power for the choke from the S terminal on the back of the alternator. You can also splice into a switched power source in the steering column wiring harness.

 

[tony-muscle]

In my car it was spliced into the switched side of the coil. This wire runs right by the choke.

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[jpaz]

I used the wire for the throttle position solenoid.

 

[TheRktmn]

Ford used the STA (stator) post on the alternator for a reason. 

The choke is supposed to open as the engine warms up. If you use a switched source then the choke is heating and opening as long as the key is on.  If the engine stalls while warming up it still opens, making the choke useless. The STA post only powers the choke when the engine is running, as an 'automatic' choke was intended to work.

Of course there is an ongoing www argument about Edelbrock calling for 12V on their choke and the STA puts out about 1/2 the B+ voltage in A/C form but many have tested it and the STA opens withing seconds of the 12V.

I have always used the STA on my Ford, Holly, Edelbrock and now Summit chokes and they work fine.

 

[jscott]

I see but how often is the key on but not the engine running?  With me it is on when the engine is running, I do not sit in the car and listen the radio.  And if that is the case then I would assume switched power would be oK?  Or does the STA regulate the power to a lower input?

 

[73pony]

Like jpaz, I used the throttle position solenoid as well and have never had an issue. 

 

[MKSpeedlab]

Like jpaz, I used the throttle position solenoid as well and have never had an issue. 

I when the car had the Edelbrock I also used the throttle position solenoid wire.