Ford charging light not going out

[Scott_Tucker]

I've got a 1967 Shelby Cobra whose alternator light will not go out. The system is charging. One side of the light is wired to key-on battery power and the other is wired to the stator. When the alternator starts spinning, enough voltage should be produced at the stator terminal to turn off the light, correct?

If anyone has a schematic of an externally regulated alternator or the regulator (points type) I would be ecstatic! It's going to Pebble Beach this weekend and I'm not content with second place.

 

[eljefino]

Are you 100% sure you have a stock alt and not a self-exciting ("hot rod") one? They might have changed something in the little "brush module" for example.

 

[Roadkingnc]

Stator voltage should be half of charging voltage. Im pretty sure the switched oower should br going through the light circuit, the stator wire goes to the regulator.

 

[javacontour]

If you are really connected to the stator, aren't you getting AC? I think you need that end connected to a DC source so the voltage drop across the light is zero and it goes out.

 

[TFB1]

The regulator may be bad, coil that operates contacts for light could be open... Check S term to ground(connector plug disconnected) if it's more than a few ohms that's the problem...

I believe the Shelby has both gauge & light??

 

[Scott_Tucker]

Yes, it has a light and an ammeter. Thank you very much for the diagram, it was exactly what I am looking for.

 

[mechtech2]

Does the light dim at all when started?
One leg of the alternator may be dead [diode].
All sorts of things, actually.
What are the voltages at rest and started at various RPM?

 

[Scott_Tucker]

I was able to fix it. I took the cover off the voltage regulator and found that the arm for the field coil was bent too far upward and the coil could not close the contacts. Once I bent it back, it works properly. I'm not sure how it would get bent since the cover looks like it had never been off, but I've seen stranger things.

Thanks for all your help guys, especially TFB1 - that diagram was indispensable.

 

[TFB1]

Originally Posted By: Scott_Tucker

Thanks for all your help guys, especially TFB1 - that diagram was indispensable.


And you're welcome, good luck at the show...

 

[Scott_Tucker]

If we win, you can say you helped with a Pebble Beach winning restoration ;-)

 

[bdcardinal]

Pics of said Cobra?

 

[Scott_Tucker]

http://www.clubcobra.com/forums/originality-forum/111419-csx-3360-palo-alto-concours-2011-a.html

 

[bdcardinal]

Absolutely beautiful car. Is that based off of a Fox chassis by chance?

 

[Scott_Tucker]

That car is the last original Shelby Cobra. Everything after that is a reproduction. It is for sale for $2 million.

And, no, I do not own it. I just restored it.

 

[TFB1]

Originally Posted By: Scott_Tucker
That car is the last original Shelby Cobra. Everything after that is a reproduction. It is for sale for $2 million.

And, no, I do not own it. I just restored it.


Meh, pocket change...

Kidding aside, it's gorgeous, nice work...

I recently helped with the build of a Superformance clone(I was the wiring guy)... It's powered by a 468ci in alum FE, needless to say it is a very nasty boy...