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Installing an electric choke on my Speed Demon. Where is the best place to take Swiched (+) and Negative ground underhood? I want the wiring to look clean and simple. Would like to tape it to the oil and coil wire that runs between the intake manifold and the Valve cover on the Pass. side.
 

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The electric choke should get a full 12v and only when the key is in the "on" position. This leaves ONE wire in the whole car that fits the bill. The red/green ignition wire between the ignition switch and the resistor wire, unless of course, you have or are going to elminate the resistor wire.

Anywhere else and your coil will receive more than 12v (which means it opens early), less than 12v (which means it opens late), or it will be on with the key in "accessories" (which means it work at all when you need it, if you ever use "accessories").

If you elminate the resistor wire (only do this if your coil and your distributor can handle them ... stock ones can't), you can just hook it to the coil wire.

For the ground, just use one of the choke housing screws.
 

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I used the + wire from teh coil (went MSD) and grounded it to the carb stud. I figured the + wire was there and unused... made the install clean and quick.

Of course... no MSD means you gotta do it different.
 

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Discussion Starter #4
Yup-- I only have 6.5 volts to the coil due to the resistor wire.. Looks like I will have to pick up red/green stripe on the other side of the resistor wire, near the switch.
 

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Mark,
A guy once told me the electric choke (+) goes to a small terminal on the alternator. I do not have an electric choke but you might want to see if this is correct before you run extra wire.
Rick
 

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I agree with what was said in the previous posts regarding the electric choke hookup....
A. Anything connected to the "on/run" position of the ignition switch after the resistor wire (pink) will deliver less than 12 V. This includes the coil and "I" terminal of the solenoid. The "I" terminal only delivers 12V (to the coil) during the "cranking" phase of engine start up.
B. The "stator" post on the alternator will also deliver less than 12 V. IIRC, on carburated 5.0 Fox Mustangs, they may pick up the choke from the stator, but those chokes are 7 V chokes.
C. The only switched 12V source is at the ignition switch (red/green wire) before the pink wire connection.

That being said, I have my MSD box and aftermarket tach connected to the "red/green" ignition switch where the pink wire was previously connected in order to supply those units with a 12V switched source. I elected to not use that same source to power the electric choke too. So I connected my choke to the "acc" post on the ignition switch as its capable of handling more "accessories". I rarely use the radio or other accessories with the engine off, so its not a big issue with the Fastback. However, just in case, I wired a small switch (under the dash, relatively obscure) in the circuit so that I could disable the choke in the event that I did want to run accessories with the engine off. The switch emits a green glow when "off" with power in the circuit to remind me that the choke is in the "disabled" position. In the several months since the car has been completed, I haven't yet used the switch, so I'm comfortable with the scheme.
 
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