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Electric Choke Operation

Tman

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Oct 28, 2006
Messages
298
Loc.
Washington Twp., MI
I have a Motorcraft 2150 Carb w/ an elec. choke and I was wondering how I hook it up, or do I not have too. Is this blade connector power to the choke?? (see pic) if not what is it and where does it get hooked too?? I can't find any decent 2150 diagrams anywhere online. Thanks
 

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kps74 bronco

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Loc.
south jersey,medford
Just need to hook it up to 12v key on power.I had mine hooked to the i term ,but any 12 volt sorce with the key in the run position will work.Just make sure its not hot with the key in the off position or it will burn out the heating coil .Ken
 
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Tman

Tman

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Washington Twp., MI
But is that blade connector in the picture the power source for the choke?? I read some chokes had heaters on them, I was wondering if it could be for that?
 
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Tman

Tman

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Washington Twp., MI
Ok, thats what I did, I hooked it up to my cigarette lighter/dome light circuit, I figure since I don't have a dome light, I should be good. Thanks for the feedback.
 

Bronco_46256

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Oct 12, 2003
Messages
428
Loc.
Elkhart
For just a few bucks, you can add manual choke and know when its on and when its off. Also, a solid 12V power supply scares me. A good friends jeep fried a harness when the choke wire worked loose a while ago.

Good place to get a manual choke kit is Pep Boys. Also picked up a truck style heavy duty push/pull cable and it made even better.
 
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DonsBolt

Bronco Guru
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May 5, 2005
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5,249
Loc.
Chestnut Hill, Mass
I agree find a different power source, the elctric choke is just a spring that opens when power is applied to it. It actually gets warm when you power it up.

The way you have it now the choke will never close, and it will fry the choke or your electrical system.

Find a 12 volt source that is only on when you start the truck.
 

70_Steve

Old Guy
Joined
Dec 13, 2002
Messages
8,317
If you can get the electric choke to work properly, it's much easier than a manual choke. I have a manual choke on my Carter AFB, but only because that's what was installed when I bought my Bronco.

Stock, the source for the electric choke was the Stator connection on the alternator. By using this source, the electric choke only get power when the engine is actually running, not just sitting with the key on. Here's part of a wiring diagram for the 75-77's that show this connection.
 

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Tman

Tman

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Washington Twp., MI
Which one is the Stator connector, I believe this is the stock alternator, it has a Blue and Red connector, both the same size, and a smaller Orange connector(see pics)
 

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lbuch40

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Black Hills
I have an electric choke, but would like to hook up my manual choke cable which is laying there unused. Can I have both? Where does the cable connect on the carburetor?
 

70_Steve

Old Guy
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Dec 13, 2002
Messages
8,317
I have an electric choke, but would like to hook up my manual choke cable which is laying there unused. Can I have both? Where does the cable connect on the carburetor?
Hi and welcome to CB.com!

Nothing like reviving a old thread!

I'm not sure I can even imagine how an automatic choke could operate with a manual choke. I suppose you could rig up some linkage that would allow the manual choke to override the automatic choke, to either push the choke plate to the closed or open position.

Is there some reason why you'd like to use both the manual choke and the automatic choke? Usually if I find something on my Bronco that's "laying there unused" I remove it!
 

blubuckaroo

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Jun 11, 2007
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Loc.
Ridgefield WA
The stator "Y" connection, on the back of the alternator, is the correct point of connection for a factory electric choke. It provides around 7 volts. The stator terminal is usually marked "stator" on the case. A 12 volt source is needed for aftermarket carbs to work properly.
 

lbuch40

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Oct 6, 2013
Messages
113
Loc.
Black Hills
Automatic choke not working

Hi and welcome to CB.com!

Nothing like reviving a old thread!

I'm not sure I can even imagine how an automatic choke could operate with a manual choke. I suppose you could rig up some linkage that would allow the manual choke to override the automatic choke, to either push the choke plate to the closed or open position.

Is there some reason why you'd like to use both the manual choke and the automatic choke? Usually if I find something on my Bronco that's "laying there unused" I remove it!

Upon further inspection I realize that I do NOT have an ELECTRIC choke. There is no wire going to the bi-metalic spring. I have a picture, but have not figure out how to insert it into my reply. At any rate, it does not appear that the choke is closing into the "cold start" position like it is supposed to.
 

66broncoCT

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Torrington, CT
Sounds like you have an "automatic" choke then. Not electric, but kinda the same principle. They use a piece of pipe wrapped around the passenger exhaust manifold to provide hot air to that bimetal spring which opens the choke. If you don't have a pipe going from your exhaust manifold, the PO probably adjusted the choke to never close otherwise it wouldn't get hot enough to ever open. So you either have to adjust the choke closed and add the heater pipe in or go with a manual choke. Might be a kit available online to convert it to electric also, I'm not sure I've got a efi straight six so nothing to compare it too.
 

lbuch40

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Messages
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Black Hills
Sounds like you have an "automatic" choke then. Not electric, but kinda the same principle. They use a piece of pipe wrapped around the passenger exhaust manifold to provide hot air to that bimetal spring which opens the choke. If you don't have a pipe going from your exhaust manifold, the PO probably adjusted the choke to never close otherwise it wouldn't get hot enough to ever open. So you either have to adjust the choke closed and add the heater pipe in or go with a manual choke. Might be a kit available online to convert it to electric also, I'm not sure I've got a efi straight six so nothing to compare it too.
Yep. I found the tube that comes off the exhaust manifold and goes up to the coil. Also, there is a clip that holds the heater hose right next to the black spring housing.
So I guess I need to figure out how to adjust the "automatic" choke so that it is closed when cold and opens up when warm.
Personally, it seems like the manual choke would be more reliable. As I recall.....some of the early broncos had a manual choke (as mine is labled) and some other years had the dash bezel labled as "Throttle". Not sure how they differed in hook-up and function.
 

lbuch40

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Oct 6, 2013
Messages
113
Loc.
Black Hills
Yep. I found the tube that comes off the exhaust manifold and goes up to the coil. Also, there is a clip that holds the heater hose right next to the black spring housing.
So I guess I need to figure out how to adjust the "automatic" choke so that it is closed when cold and opens up when warm.
Personally, it seems like the manual choke would be more reliable. As I recall.....some of the early broncos had a manual choke (as mine is labled) and some other years had the dash bezel labled as "Throttle". Not sure how they differed in hook-up and function.
Is there a "procedure" for adjusting the automatic choke?
 

70_Steve

Old Guy
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Dec 13, 2002
Messages
8,317
Upon further inspection I realize that I do NOT have an ELECTRIC choke. There is no wire going to the bi-metalic spring. I have a picture, but have not figure out how to insert it into my reply.
Do you not have an electrical connection on the black choke housing, as picture in the first post of this thread?

To post pictures, either become a Contributor, at $12 per year, or upload the picture to a hosting site like Photobucket or Supermotors, then insert the link to the pic in the post using the "Insert Image" icon (the one that looks like a post card).

To adjust the choke, loosen the three screws that hold that black plastic housing in place. Rotate the housing until the choke place is nearly all the way closed. Then... Try it. Run the engine until warm, and verify the choke plate opens fully. That should happen regardless of the starting point of the choke plate. The adjustment is more for the cold start. The choke plate should open fully when warm regardless.
 

lbuch40

Contributor
Jr. Member
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Oct 6, 2013
Messages
113
Loc.
Black Hills
Do you not have an electrical connection on the black choke housing, as picture in the first post of this thread?

To post pictures, either become a Contributor, at $12 per year, or upload the picture to a hosting site like Photobucket or Supermotors, then insert the link to the pic in the post using the "Insert Image" icon (the one that looks like a post card).

To adjust the choke, loosen the three screws that hold that black plastic housing in place. Rotate the housing until the choke place is nearly all the way closed. Then... Try it. Run the engine until warm, and verify the choke plate opens fully. That should happen regardless of the starting point of the choke plate. The adjustment is more for the cold start. The choke plate should open fully when warm regardless.
Thanks for the procedure. Sounds pretty simple. There is no electrical connection on the housing. But there is an aluminum tube coming off the exhaust manifold.

I will go give it a try.
 

70_Steve

Old Guy
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Dec 13, 2002
Messages
8,317
There is no electrical connection on the housing. But there is an aluminum tube coming off the exhaust manifold.
The bimetal coil inside the choke housing heats up two ways. One of them is by hot air from the exhaust manifold. There should actually be two tubes going to the exhaust manifold. One comes from the top flange of the carb, as a fresh, filtered air supply. The other goes from the exhaust manifold to the choke assy, and is usually, or at least, originally, insulated. Inside the choke housing is a small hole that supplies vacuum to the choke assy. That vacuum pulls fresh air down to the exhaust manifold where it gets heated, then drawn up to the choke assy to heat up the bimetal coil and open the choke.
 
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