65-66 Electric Choke Wiring Idea

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Lee Craner
Posts: 87
Joined: Sat May 04, 2019 11:42 pm
Location: Las Vegas, NV

65-66 Electric Choke Wiring Idea

Post by Lee Craner »

The problem: I needed to wire up the electric choke for my replacement Edelbrock carburetor and I do not like to splice wires into the original wiring harnesses. The solution: use the unused "I" terminal on the alternator regulator to supply the necessary switched 12V to the choke.

Note that my solution will not work on 64 and prior alternators, since these years use the "I" terminal. I also use an electronic regulator, not the OEM mechanical regulator, which made the modification much easier.

Even though the "I" terminal is not used in the 65 and 66 Fords, it is used by the regulator so that it would to be compatible with earlier model vehicles that need the "I" terminal. Therefore, the first step was to isolate the "I" terminal from the rest of the regulator circuit by cutting the printed circuit trace at the terminal's rivet. An Xacto knife works well for this purpose.
Trace cut small.jpg
Next was to add a fuse holder for the choke circuit. I used a 10 amp fuse for protection. This fuse is important. If the choke wire comes off the choke and shorts to ground with the ignition switch on, the results could be disastrous.
Fuse holder installed small.jpg
One end of the fuse is wired to the "I" terminal rivet and the other end to the "S" terminal rivet. Note that for the 65 and 66 alternators, this "S" terminal supplies regulated 12 V whenever the ignition switch is on.
Fuse holder wired small.jpg
The hood of the regulator connector was removed to expose the connectors.
Original connector small.jpg
A small hole was drilled into the connector opposite the "I" terminal on the regulator to accommodate a new female spade connector and a blue 18 ga wire that would be connected to the choke.
Modified connector small.jpg
The hood was reattached and the modified connector attached to the regulator.
Connector installed small.jpg
The other end of the new blue wire, of course, is connected to the spade lug of the Edelbrock choke.
Lee
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Alan H. Tast
Posts: 3425
Joined: Wed Aug 20, 2003 10:52 pm
Location: Omaha, NE

Re: 65-66 Electric Choke Wiring Idea

Post by Alan H. Tast »

Lee: Kudos for a very well thought-out solution to getting power to the choke. I'd like to develop this into an article for the Scoop. IM me for questions I have in order to start putting the article together.
Alan H. Tast, AIA
Technical Director/Past President,
Vintage Thunderbird Club Int'l.
Author, "Thunderbird 1955-1966" & "Thunderbird 50 Years"
1963 Hardtop & 1963 Sports Roadster
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