Briggs and stratton voltage regulator wiring diagram

  • #1

Hello,
I have a two wire Briggs and Stratton rectifier as shown in photo that converts AC power from the alternator to dc to charge battery while the engine is running.
The 11.5 hp Briggs and Stratton engine has one wire coming from the alternator. Can someone tell me please which wire ( yellow or red) the alternator wire connects to and which one connects to the battery to keep it charged. Thanks

Briggs and stratton voltage regulator wiring diagram

  • #2

Red is the normal colour for positive for DC, so red to battery. Yellow is commonly used for AC, so yellow to alternator.

  • #3

Thanks for your response, appreciated. I know that the DC cable can be connected to key switch ( R for regulator) to charge battery once it is turned on and while engine is running but can it be connected straight to positive terminal on battery instead ?
Also does the rectifier normally have a limit on the DC current coming out of it (around 12v) and does it only allow current one way? Thanks in advance.

  • #4

I guess you have one black wire coming out of the stator? Harry is bang on with his response and the black changes to yellow.
Personally I'd go for an ignition switch system as I have had on occasion a battery leak back through the rectifier / regulator but whether that was due to a fault I don't know.....the ignition switch cuts everything dead I think.
That wee device of yours has two functions - it converts AC to DC and also limits the voltage to around 14v when running fast. The engine doesn't produce enough current for anything to get hurt and yes, it only allows current one way (theoretically!)
John

  • #5

That wee device of yours has two functions - it converts AC to DC and also limits the voltage to around 14v when running fast. The engine doesn't produce enough current for anything to get hurt and yes, it only allows current one way (theoretically!)

I'm not convinced it will actually limit the voltage, but if it does, to do that it would need to be firmly bolted to the chassis/ negative.

I have had bikes where the alternator output is just rectified and connected across the battery, without any regulation at all. I've had bikes which had 3-phase alternators, where the output was simply limited by shorting the surplus voltage to chassis/negative.

  • #6

That item is actually classed as a voltage regulator and it gets its chassis connection via the sleeved bolt hole in the middle.
John

  • #7

If it helps, have a look at the attached. You might have to pull the flywheel off though, to see what sort of windings you have in the stator.

  • alternator_id.pdf

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  • #8

I also have a much larger file (13 Meg) with wiring diagrams for just about every alternator they ever did. However, I just get an error message when I try to upload it. Is there a limit on the size of file I can upload on here? (It's a PDF). Failing that, PM me an e-mail address and I can send it to you.

What is the red wire on a Briggs & Stratton engine?

RED WIRE - This is your DC cable, it should be connected directly to positive power on your battery. This wire charges your battery. BLACK WIRE - This is the engine kill switch, It needs to run to an ON/OFF switch and then run to earth. DO NOT CONNECT THIS WIRE TO POSITIVE POWER!

How does a lawn mower voltage regulator work?

Once the engine is running it drives a small alternator whose rectified output is a low power capacity pulsating DC voltage capable of recharging the battery. To prevent overcharging of the battery, a voltage regulator module is introduced between the alternator output and the input to the battery.

How do you test a Briggs and Stratton alternator?

For the easiest alternator test, simply turn on the headlights to your lawn mower or outdoor power equipment. Then, turn off the engine. If the lights dim, the alternator works. If not, it doesn't.