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Discussion Starter · #1 · (Edited)
69 Mustang, trying to wire up the alternator, connector broke, ordered new one for 69 no tach. The white wire dangling is cut completely further down the harness. The new wire has 2 connectors and a ground, is this enough to hook up the alternator? THX
 

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Ray,
Here is a diagram for the Ford 1G charging system with charge indicator light:


Paul
 

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67 coupe, 69 Sportsroof, 86 hatchback
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So that's your original? I think that's cobbled in from a different Ford. A picture of the new one would help. Or have you not received it yet?
Anyway, you need three wires and ought to have a fourth.
First is easy, big fat wire to the battery.
Next, the orange wire is the Field to the regulator.
Then the white wire is to the Stator. Yours won't work as-is.
The fourth is a good ground. On that harness it is neatly provided by that shiny metal tab that bolts the whole thing to the alternator. Usually on older cars there isn't one at all and you have to add one. From the alternator case (there's a stud or threaded part to use) to where your engine block ground is ideal.

This is the section of your wiring harness most likely to short/overheat and potentially burn down your car. You want to fix it right and not be cobbling things together.
 

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Do you have the diagram for the version with the gauge? That’s the one the OP needs, tach cars had the light, the rest had a gauge.


Note that on some cars the wire from the alternator FIELD terminal to the regulator F terminal is white not orange (both diagrams). Also keep in mind that these are block diagrams, the harness connectors are NOT shown.

Paul
 

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That reminds me. I ran across a wiring issue in a partially assembled car once. Everything about the car said the wiring was supposed to be like the second diagram. But it wouldn't charge for love nor money. So in addition to it being correctly wired like that diagram, just for the heck of it I added the missing and unnecessary "S-Stator" wire as in diagram one. It immediately started charging correctly. Everything seemed fine and I had too much time into it already so I made the wire neat and more permanent and moved on. I never looked further into it to see what that was all about but I obviously didn't forget either. It always bothered me a bit that I never figured out why.
 

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That reminds me. I ran across a wiring issue in a partially assembled car once. Everything about the car said the wiring was supposed to be like the second diagram. But it wouldn't charge for love nor money. So in addition to it being correctly wired like that diagram, just for the heck of it I added the missing and unnecessary "S-Stator" wire as in diagram one. It immediately started charging correctly. Everything seemed fine and I had too much time into it already so I made the wire neat and more permanent and moved on. I never looked further into it to see what that was all about but I obviously didn't forget either. It always bothered me a bit that I never figured out why.
In either setup the connection at the regulator S terminal is to supply voltage to the field relays energizing coil so that its power contacts close. The closure of the field relay power contacts allows battery voltage to be metered to the alternator's field windings - without which the alternator cannot product current. In your case study I would have to speculate that the there was an open in the supply circuit to the F terminal - perhaps at or downstream of the ignition switch. By wiring a second lead from the alternator stator you simply created a second path.

Paul
 

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67 coupe, 69 Sportsroof, 86 hatchback
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That was about what I guessed as it makes the most sense. I just would have liked to have had proof and I'll never be really happy about that added extra wire as fix but it was a rush job that had to roll the instant it was able.
I've been eyeballing this tool for the next time I encounter something like a broken wire in a harness. There are videos of it (and other version) in action out there that demonstrate it nicely.
https://www.aeswave.com/ECT3000-Circuit-Tracer-p9502.html
 

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Ok so further to the above, I am using a 2 wire built in reg alternator( D+ and B+). I have an Ammeter gauge and thought I had seen a diagram of how to bypass/delete the existing original regulator. Can someone sharpen their pencil a draw me a schematic?
Cheers IanS
 
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