Sisson choke with 12v conversation

[streetdemon]

I have a question for those of you that have converted their cars to 12v. I am currently replacing the wiring harness in my 1950 Plymouth P19 and I was curious if I need install some sort of resistor that is inline to the automatic choke if I convert my car to 12v? The reason I ask is I was testing the the choke and the wire gets really hot and I don’t want to burn it up. Should there be fuse inline as well? I am using a Hot Rod Wires harness and I just want to make sure I hook it up properly.

 

thanks,

Brad

[Sniper]

I did nothing to the sisson choke when I converted to 12v.  never checked to see if the wire got hot though. 

[Loren]

Are you sure it connected right?

The coil within it should only see power when the starter is running.

That’s not long enough for the wire to get hot.

[desoto1939]

A while back I did see a 12 volt sisson choke listed on Ebay. currently there isa 24volt sisson choke listed.    Even though you have converted to 12 volt the choke is only supplied a shot amt of power when the starter circuit is actuated and it send the current to energise the electro magnet to  pull the choke rod to set the choke butterfly and then as the heat from the manifold increases the bimetall plate then slowly decreases the tention and lets the choke linkage and the choke butterfly return to its open position.

 

rich Hartung

Desoto1939@aol.com

[Dodgeb4ya]

Using a screw that is too long when attaching the wire to the Sisson unit will cause a dead short to ground.

It needs to be a very short screw.

[Bryan]

My father's solution...manual cable, never hangs.

[streetdemon]

I will check the screw length tomorrow and see if the wire only has power when the starter is engaged. 
 

Thanks for for giving me a few ideas!

 

If all else fails I will install a manual choke.

[desoto1939]

18 hours ago, Bryan said:

My father's solution...manual cable, never hangs.

 

Brian can you tell me where is the choke located on your manifold? Is the choke located behind the carb or in front of the carb? from the pictue it looks as if the choke assembly is located behind the carb and close to the firewall.  If the flat spot on the manifold is behind the carb then I think you might have the wrong model sisson choke.  The wire would come in from the back of the choke body in a direction fromthe firewall. With the arm being the way it is setup it looks as if the linkage is binding.  There were two models one that mounts from the back of the carb and the other mounts in front of the car.  The front mounting was for the 49-53 Ply and some dodges. Contact me at Desoto1939@aol.com   Also do a search on Sisson choke on the Forum.  I had posted info and have helped people solve their issues.

[Bryan]

13 minutes ago, desoto1939 said:

 

   Also do a search on Sisson choke on the Forum.  I had posted info and have helped people solve their issues.

Thanks but I'd rather keep the manual choke, simple and it works. I got used to using it in the 1980s when it was running. I'm not planning on any car shows, but appreciate the offer.

Edited November 30, 2021 by Bryan