Easy
15-30 minutes
This is a geniune OEM part. The Briggs & Stratton, 10-16 amp voltage regulator is composed of metal, wiring and plastic parts. The regulator is compatible with many lawn and garden machines. This part is connected to the engine's terminals, and has been designed to manage the voltage in the device's electrical system. A screwdriver and a socket set are needed in making the removal and repair. It is recommended to refer to the manual and diagrams for repair instructions. This item is sold individually.
Regulator 845907
OEM part for: Briggs & Stratton Engines, Toro
Part Number: 845907
$66.97
In Stock
Ships within 1 business day 
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Compatibility
This Regulator will fit the following 21625 machines. Confirm this part works with your model, and view the detailed model diagrams and repair help we have to offer.
Displaying 20 of 21625 matching models.
21625 total model matches. Try the above search to narrow your results.
This is the official OEM part for the following brands:
- Briggs & Stratton Engines
- Toro
- Vanguard - Briggs & Stratton
This item works with the following types of products:
- Engine
- Generator
- Lawn Mower
- Lawn Tractor
- Snowblower
This part replaces obsolete part #: 393374, 797375, 394890 (10, 13, or 16 Amp, Depending on Size of Flywheel Magnets), 691185, 394890
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Customer Repair Instructions ?
All our customer repair instructions are solicited directly from other customers just like you who have purchased and replaced this exact part.
Battery not charging new battery
Simon - July 27, 2016
👍 89 of 91 people found this instruction helpful
Tool Type
Lawn Mower
Difficulty
Medium
Time
15-30 minutes
Tools Used
Nutdriver, Multimeter
Parts Used
On briggs and stratton twin cylinder engine, start engine up, put engine full throttle, set multimeter to dc volts, check batter voltage. Should be greater than 12 volts. If not find the voltage regulator with 2 yellow and 1 red wire coming from it. With engine still running unplug yellow wires and switch multimeter to AC volts. The yellow wires coming from under the flywheel (the thing on top that is spinning) insert test leads into that plug. Should be somewhere around 20-30 volts. If that checks out fine, plug yellow wires back together. With engine still running at high idle, unplug the red wire from the regulator. Set multimeter to dc volts. Insert one probe in red wire from regulator and the other to the frame or a good ground. Should be greater than 12 volts. If not its the voltage regulator. Remove, unplug, plug new one in bolt in place. Run mower at high idle, check voltage at battery, should be greater than 12 volts. If batter was low to begin with let mower run at high idle for 10-15 mins and recheck.
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Not charging enough to keep electric clutch engaged tractor would also stop running
james - March 30, 2016
👍 20 of 21 people found this instruction helpful
Tool Type
Lawn Tractor
Difficulty
Easy
Time
Less than 15 minutes
Tools Used
Screwdriver, Socket set
Parts Used
Take two bolts out of regulator disconnect wires. Replace bad one with new one
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Lights were dim
James - December 2, 2015
👍 6 of 7 people found this instruction helpful
Tool Type
Lawn Tractor
Difficulty
Easy
Time
Less than 15 minutes
Tools Used
Pliers, Nutdriver, A 12 PACK LOL
Parts Used
Removed the two screws securing the worn regulator, Unplugged terminals, attached new regulator and attached terminals. Bright lights again.
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Battery not charging
Carl - May 24, 2018
👍 1 of 1 people found this instruction helpful
Tool Type
Lawn Mower
Difficulty
Easy
Time
15-30 minutes
Tools Used
Socket set, Electrical connectors and crimp tool - digital voltmeter
Parts Used
1) Checked battery voltage prior to replacement of regulator
2) Checked alternator output - good
3) Removed old regulator and temporarily connected new regulator to alternator and battery through starter switch connection.
4) Checked charging voltage at battery and it was good.
5) Replaced connectors on both alternator output and and new voltage regulator input to match
6) Reconnected new regulator
7) Checked output voltage at battery and battery was charging.
2) Checked alternator output - good
3) Removed old regulator and temporarily connected new regulator to alternator and battery through starter switch connection.
4) Checked charging voltage at battery and it was good.
5) Replaced connectors on both alternator output and and new voltage regulator input to match
6) Reconnected new regulator
7) Checked output voltage at battery and battery was charging.
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Engine hardstarting after sitting for a week and newbattery went below voltage which made PTO quit
Roger - June 29, 2021
Tool Type
Lawn Tractor
Difficulty
Easy
Time
15-30 minutes
Tools Used
Pliers, Socket set, Ohm meter aka voltage meter
Parts Used
The fuel pump bolted to the side of engine 2 screws and 3 hoses to remove very easy fix.
The voltage regulator also bolted to engine with 2 bolts a 2 yellow wire connector to the
Alternator and a Single red wire connector to the battery.
After making repairs I cranked the engine with choke engaged as usual
And within 5 seconds the engine fired up it sounded so good to hear run again
Then I used my ohm meter to check the voltage at the battery it read 13.87 volts.
Now engine cranks over much faster and starts every time
So whether you order parts on line knowing the parts that you ordered
Or call customer service, they have a very knowledgeable staff they will ship you the parts you need
Also the correct and original parts at the best price around these guys ROCK
I for one am a very satisfied customer
I'm sure they can satisfy your needs as well
Till next time
The voltage regulator also bolted to engine with 2 bolts a 2 yellow wire connector to the
Alternator and a Single red wire connector to the battery.
After making repairs I cranked the engine with choke engaged as usual
And within 5 seconds the engine fired up it sounded so good to hear run again
Then I used my ohm meter to check the voltage at the battery it read 13.87 volts.
Now engine cranks over much faster and starts every time
So whether you order parts on line knowing the parts that you ordered
Or call customer service, they have a very knowledgeable staff they will ship you the parts you need
Also the correct and original parts at the best price around these guys ROCK
I for one am a very satisfied customer
I'm sure they can satisfy your needs as well
Till next time
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Battery Would not charge while motor was running.
Daniel - June 1, 2020
Tool Type
Lawn Tractor
Difficulty
Easy
Time
15-30 minutes
Tools Used
Socket set
Parts Used
Removed and replaced voltage regulator.
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Bad regulator
Edward - April 26, 2018
Tool Type
Lawn Tractor
Difficulty
Easy
Time
Less than 15 minutes
Tools Used
Socket set
Parts Used
Removed 1 10mm screw and loosened the 2nd. Unplugged the old regulator and plugged in the new one. Replaced the removed screw and tightened both.
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Battery would not charge.
Melvin - May 22, 2017
👍 2 of 4 people found this instruction helpful
Tool Type
Lawn Tractor
Difficulty
Easy
Time
Less than 15 minutes
Tools Used
Screwdriver
Parts Used
Plugged in the part and remounted it.
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All our part reviews are solicited directly from other customers who have purchased this exact part. While we moderate these reviews for profanity, offensive language or personally identifiable information, these reviews are posted exactly as submitted and no alterations are made by our team.
All our customer repair instructions are solicited directly from other customers just like you who have purchased and replaced this exact part. While we moderate these reviews for profanity, offensive language or personally identifiable information, these reviews are posted exactly as submitted and no alterations are made by our team.
Based on data from past customer purchasing behaviors, these parts are most commonly purchased together along with the part you are viewing. These parts may be necessary or helpful to replace to complete your current repair.
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