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Where is the alternator on a Briggs and Stratton 12 HP engine

Posted by markstar (My Page) on
Wed, Aug 18, 10 at 20:17

Hi have an 12 H.P. Briggs and Stratton engine #281707
When cleaning it up I noticed a broken wire laying under the starter. Based on the repair parts manual it appears to be the wire from the key to the alternator.
The manual shows a wire with a cylinder connector and labels it "alternator". I assume the alternator is some place in the engine since they do not break the engine down. What I thought I would find is the other end of the broken wire but I can not see the other end.
To clarify, from the Key there is a red wire that comes down into a cylinder connector and then it is a black wire. The piece I have is short and seems to have been melted and is at distance of the starter.

I have not taken off the heat shields on the front to see if that is where it is.

can anyone give me an idea where to find the other end that goes to the alternator and if this wire is needed, let me know.

Thanks in advance.

Follow-Up Postings:

RE: Where is the alternator on a Briggs and Stratton 12 HP engine

  • Posted by canguy British Columbia (My Page) on
    Wed, Aug 18, 10 at 20:30

The flywheel needs to be removed to access the alternator.

RE: Where is the alternator on a Briggs and Stratton 12 HP engine

But where does the wire that broke off terminate from the engine? My guess is that the wire is fine from the flywheel down to where ever it broke off to what I see on the outside lying near the starter.

What does that wire do? Is it needed since it seems it might have been broken for a while.


RE: Where is the alternator on a Briggs and Stratton 12 HP engine

Could you tell us the brand and model number of the machine this engine is in?
And I don't think you mentioned the color of the wire that is broken.

RE: Where is the alternator on a Briggs and Stratton 12 HP engine

Generally on a 28 series Briggs, alternator wiring is done one of two ways.

If machine has electric start but no headlights, a single wire will come from the engine and connect to the machine harness by various connectors (spade, QC, etc.). Provides rectified DC for battery charging.

If machine has lights, there will be two wires together coming from engine ending is a single, two pole connector. One of the wires will have a diode in series (under heat shrink) and provides DC for battery charging. Other wire provides AC for lighting purposes.

If you have a single broken wire, it probably goes to the mating connector which in turn connects to the connector coming from the engine.

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