hi guys...

just bought a rebuilt 1barrel carter carb for my '71 ford f100. it's got an electric choke on it -- one lead coming out with a male spade connector. so the question: where the heck do i connect it?

-richard

 

The Ford trucks I have worked on have it hooked up to the "sta" (stator) terminal of the alternator.

Sparky

 

Hey,

I agree with sparky, also, it should be around 8-9 volts on that terminal when the truck is running, not 12-14 volts.

-Brents

 

I was wondering what use that terminal was...in my '65 shop manual it refers to it as the stator neutral. One end of each of the three phases goes to a diode pair but the other ends all connect together which is, if you're interested, the neutral in a wye-connected 3-phase system.

As someone else posted you would only see 1/2 (or maybe it's 1/1.732 ?) of the alternator output voltage referred to the case ground, and only with the engine running. Would that be enough voltage to have the electric choke pull-off in a reasonably quick time?

Does anyone know where in the wiring harness the other end of the "STA" lead is? I have ordered a wiring diagram but it's not here yet.

I have my Echlin replacement hooked up to 12 volts from the ignition switch. This lets the choke open if you sit with the key on, even if the engine is stopped, which can be very useful if it's flooded.

 

Other end usually is near passanger side of center against the firewall. On my '79 there's a plug for the electric choke and an anti-diesal/stall/what ever you want to call it solenoid. The wire for the solenoid is ~12V with the ignition on. The other wire is from the Alt. stator ~6V - engine on only -as posted previously.

 

It all depends on what type of electric choke system you have. Some are designed to run off the Stator voltage, which is around half the battery voltage. Others and most aftermarket units run directly off +12 volts.

 

alright...i connected it to the "i" post of the starter relay. how deoes that sound? better yet, anyone know how to test it? (other than wait for a freezing day...i'm out on the coast, still warm!)

 

You might burn out the resistor wire to the ignition coil if you hook it up on the "i" terminal. If you check it, you will find with the truck running, you don't have a full 12v there either. I can't sustantiate what I said about burning up the resistor wire, but it will put an extra load on it, and I don't like hooking stuff to the ignition circuit because it's too important a circuit to mess with.

 

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Every schematic I looked at showed the choke wire going to the BK/W wire that runs to the Alt and the Volage Reg.

Dennis

78 F-150 429CJ 465,000 KM.(Original Owner)
68 Mustang 289 Sunlit Gold 80,000 Miles(second Owner)
64 1/2,260 Pre-World's Fair Mustang #8092
64 Fairlane 500 S/C,waiting for a 390 4-Spd

If The Girls Don't Find You Handsome,
They Should At Least Find You Handy!

 

thanks...guess i'll try the b/w wire idea and *not* mess with the ignition circuit.

 

 

why not connect it to the positive side of the coil, theres 12volts there with the key on.
just an idea

 

Ok I checked my schematics and they all show thw electric choke hooked up to the "sta" terminal of the alternator using a black wire with a white stripe. They also show a connection using the same colored wire to the voltage regulator, if the truck has an idiot light instead of an ammeter. But even then the choke is still hooked to the "sta" terminal.
As for a lower voltage that is most likely why it is hooked to the "sta" terminal. Since the electric choke is only a heater coil the lower voltage will heat it up slower than when using 12 volts, thus keeping the choke on longer. Longer meaning the pre-determined time the engineers decided on As for an aftermarket electric choke they may well be designed for 12 volts, again one of those engineer things.
I guess what I am saying is.... If it was my truck and it was a stock choke heater I would hook it to the "sta" terminal. If it was an after market I would try and find out what voltage it required.
However, I wouldn't hook anything to the ignition circuit anywhere, especially the coil +. Cause if it happens to draw too much current "poof" the truck's fuel to noise generator, aka engine , dies and you coast to a stop wherever you are.

Sparky

 

Whoops... darn glasses That should be a white wire with a black stripe.

Sparky

 

Ok, here’s the deal on your electric choke. If it’s a factory unit, it’s called an electric assist choke and hooks up to the stator for around 7 volts. They still require the old-fashioned hot air tubes from the exhaust manifold to the choke housing. The choking action is still accomplished using the hot air tubes and the electric assist only helps to pull off the choke faster. Inside the electric choke housing is a temperature switch and a heating element along with the bimetallic spring. The bimetallic spring is heated by the hot air sucked from the manifold tube and slowly turns to open up the choke plate. The electric assist only helps to open up the choke faster. The switch in the choke housing is open below 60 degrees, closed between 60 and 80 degrees and open again above 80 degrees. So in operation when its below 60 degrees there is no electric assist and the choke works the old-fashioned way off the exhaust manifold heat. Between 60 and 80 degrees the electric assist comes on and speeds up the pull-off time. Once above 80 degrees the choke is open and the electric assist turns off. The choke remains open because it is still sucking hot air from the manifold tube to the bimetallic spring.

Electric only chokes do all the choking action by themselves and do not require the exhaust manifold heat tubes. They are on all the time and should be powered only when the ignition is turned on. The housings usually say +12V right where the connector plugs in. Hope this all makes sense.

Barry