Key On 12volt for electric choke

[tanman]

Is there a way to get this from the solenoid on the firewall? Should it have a fuse and/or relay in the circuit?

I can't tap the alternator it is a 3G single wire alternator.

I don't want to run it from the driver side if possible.

Should I just start metering for 12 volts with the key on?

Should it be 12volt with the key on but zero volts when the starter is engaged?

I'm really having trouble finding a clear answer on the web.

Thanks as always!

[ArdWrknTrk]

There is no 'key on' at the starter relay.

If you have a Motorcraft choke coil why don't you tap the stator wire of your 3G, the same way it was wired stock?
They do it this way so the choke only gets power if the alternator is turning.

If you have an aftermarket Holley or Edelbrock carb with 12V + & - spades on the choke maybe you're better off to run a wire from the ignition switch or one of the unused 'hot in run' sockets in the fuse box?

[tanman]

I think the fuse panel may be my best bet. There is no other connection on the alternator. It’s connected to the hot side of the starter solenoid. It’s a Powermaster single wire brand.

Can I just leave it disconnected for now? The weather is still warm and I’m eager to fire this thing up after all the changes.

Is the choke just for cold weather?

[ctubutis]

I use the factory-supplied red/yellow-dots wire for my aftermarket 12v choke, that circuit was originally used by various under-hood, engine-control solenoids.

[ArdWrknTrk]

A 3G alternator has a regulator plug with excite, stator and sense connections. Also a separate stator connector.
'one wire' is a GM aftermarket thing that has nothing to do with any generation of Ford alternator.

You definitely want a functional choke regardless the season.
Ford air cleaners are calibrated at 105°

Chris, I assume that's fuse 18? (there are no dots on harnesses in 1986)

[ArdWrknTrk]

Looks like 640 is already used for the bowl vent solenoid.
Should be right there (edit: forward of the carburetor) as described at the top of pg. 63.

[85lebaront2]

You need a source that will not heat the choke until the engine is running. If you had stuck to Ford parts it would be easier, but since you chose a GM alternator, the solution is a normally open oil pressure switch, not one that grounds. GM and Chrysler both used them GM on cars with electric fuel pumps, Chrysler on the early carbureted 4 cyls. Chrysler's is a 3 terminal with one for the idiot light and two NO pins for the electric choke.

[ArdWrknTrk]

I think Powermaster offers a 3G bodied alternator that is wired to bootstrap itself.
While this means you don't get any substantial output until you hit a threshold of perhaps 2,500 alternator rpm, there should still be a stator connection that can be tapped for the choke.

Wiring the choke through an oil pressure switch will definitely serve the same purpose and may be less complicated.  

[kramttocs]

He may have the same Powermaster 3G 1 Wire I have and you're right Jim, while the harness is molded in place the wires are still exposed and could be tapped into.

I like the oil pressure switch triggering a relay option myself. The 460 makes that easier though since it has an oil pressure switch already.

[85lebaront2]

With the switch I listed, Chrysler 2.2L carbureted engines it keeps the idiot light if used, and powers the choke without using a relay. It will even work on a 2G alternator or a 1G.

[ARM Ashby]

I have a 3G 130 amp on my 86 F350 7.5 I used the white/black wire off the alternator just like the stock 1 G. This 7.5 volts. It will also run a 12 volt choke coil.

[Jesse3877]

I have an edelbrock carb with electric choke. I used a add-a-circuit at the radio fuse and ran wire through existing hole in firewall. Works just fine but was considering using my stator terminal on 1G alternator, even though edelbrock says not to, so I can hide the wire easier.