I have a 130 amp alternator, the kind that goes in an early/mid 90's truck, and I've got it all in pieces on the workbench. I have a book that talks about testing alternators, and it says there should be a low resistance between any two of the three stator wires. But this Ford stator has not three but SIX wires! When I ohm-checked them with my Fluke meter, some of the wires show 0.1 ohms between them, but mostly they show an open circuit. So, either I've got multiple broken windings, or Ford alternators are different!

 

Did you take notes on how they were wired when you took it apart? 6 is divisible by 3, so there is probably a combination series or parallel that the 6 wires are hooked to give 3. All alternators are 3 phase, you should get a reading between any two of the 3 just like you read. You just have to group your 6 wires into the right combo to get 3.

 

I'm thinking that the stator circuit is ground, windings, then the diodes,and on to the output. Three wires are for the ground.

 

This may be of some help.

 

That above diagram doesn't look right does it? It has the output wire grounded?

 

Nice catch. Never noticed that. Here is a 1G and the internal stator windings should be the same. It's showing a capacitor isolating B+ and Ground.

 

The above image had the Cap left out:


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Thank you. Replaced my file photo.

 

Here's a diagram of a 6 lead 3 phase motor. One diagram is for a "y" connection(looks sort of like a y) and the other connection is for delta(looks like a triangle).

If you notice, the above alternator diagrams are wired "y". So if you go by this diagram, you would hook the alternator up like the diagram on the left where it joins 4,5,6 together.

 

Found this the Wye design. Three diodes are grounded then one of each stator wire goes to the output of one of the ground diodes. Three off the stator wires sre put togetherhttp://www.autoshop101.com/forms/alt_bwoh.pdf.

 

This drawing is also incorrect.
A 1G has 6 diodes.
The center of the "Y" is just 3 wires just crimped together and is not bought out of the case.
The Stator is connected to an output winding.
The center of the "Y" is basically a ground.
Jim

 

Alternators are single-phase or polyphase.
Polyphase means dual windings.
3G are parallel polyphase ALT.

AC Alternators About - Engineers Edge

see the bottom drawing

You MUST reconnect the leads in parallel or the voltage output will double and might burn out the diodes if the PIV (peak inverse voltage) is exceeded. A series connection will add the voltage of each winding together.

The parallel design gives higher current and lower voltage.
Jim

 

Poly means "MANY" or more than one not dual.