Husqvarna TYTH20K46 Briggs engine swap wiring issue. HELP!

foleif

Forum Newbie
Joined
Sep 13, 2022
Threads
1
Messages
4
  • / Husqvarna TYTH20K46 Briggs engine swap wiring issue. HELP!
About six years ago I was gifted a Husqvarna TYTH20K46 with a Kohler engine that had thrown a rod. I thought, sweet I'll have the janky mower shop down the street throw in a used motor for cheap and I'll be all set. Well it kind of went that way but now six years later that motor is toast. They swapped in a very tired 25 HP (yard man) V-twin Briggs. I have recently purchase a brand new 20HP v-twin Briggs as the price was great, I knew the shaft and mounting was the same and I assumed since they already converted to a Briggs that would be easier. Problem now is that I just flat out cant wrap my head around the wiring and really hoping someone here can help a guy out.

first pic is the existing Husqvarna wiring harness that went to the last Briggs motor (orange and purple were merged with one wire from previous motor) on the left and the new Briggs harness on the right. (Grey, black, green, orange, red)
second pic is the info for the new motor
3rd pic is of the old Briggs motor (conveniently upside-down)

Really hoping someone here can help me out as my lawn is looking pretty wild at the moment!
Thank you.
 

Attachments

  • harness.jpg
    harness.jpg
    209.4 KB · Views: 7
  • new briggs.jpg
    new briggs.jpg
    195.4 KB · Views: 6
  • old briggs motor.jpg
    old briggs motor.jpg
    356.4 KB · Views: 6

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
  • / Husqvarna TYTH20K46 Briggs engine swap wiring issue. HELP!
Before you get too deep into this project you will need to swap the alternator from the old engine into the new engine as the new engine has a low output that will not be able to keep up with the mower when it is running plus keep the battery charged
While the blower housing is off the old engine note which wires went to what items
One wire goes to the coils , one wire goes to the carburettor and one wire goes to alternator ( via the rectifier )
Then check the old plug and put tags on the MOWER side so you know which wires to join to what
To do the job properly you should remove the terminals and swap their position in the plugs.
leave the magneto wire disconnected at the magneto and when you have finished with the plug check that the magneto wire is either open ( not power or ground ) with the key in the on & start positions and ground with the engine in the off position.
A good mower shop would have pulled the plugs apart & swapped terminals around so it would be plug & play in future or fitted a cross over sub loom so the mower & engine plugs remain the same .
 

foleif

Forum Newbie
Joined
Sep 13, 2022
Threads
1
Messages
4
  • / Husqvarna TYTH20K46 Briggs engine swap wiring issue. HELP!
Before you get too deep into this project you will need to swap the alternator from the old engine into the new engine as the new engine has a low output that will not be able to keep up with the mower when it is running plus keep the battery charged
While the blower housing is off the old engine note which wires went to what items
One wire goes to the coils , one wire goes to the carburettor and one wire goes to alternator ( via the rectifier )
Then check the old plug and put tags on the MOWER side so you know which wires to join to what
To do the job properly you should remove the terminals and swap their position in the plugs.
leave the magneto wire disconnected at the magneto and when you have finished with the plug check that the magneto wire is either open ( not power or ground ) with the key in the on & start positions and ground with the engine in the off position.
A good mower shop would have pulled the plugs apart & swapped terminals around so it would be plug & play in future or fitted a cross over sub loom so the mower & engine plugs remain the same .
Welp...old engine is long gone unfortunately. For curiosity sake what would be the purpose of installing a low voltage alternator on an engine as opposed to a high output? What's the purpose? I had absolutely no idea that lawn mower engines would be this complicated.
 

foleif

Forum Newbie
Joined
Sep 13, 2022
Threads
1
Messages
4
  • / Husqvarna TYTH20K46 Briggs engine swap wiring issue. HELP!
Welp...old engine is long gone unfortunately. For curiosity sake what would be the purpose of installing a low voltage alternator on an engine as opposed to a high output? What's the purpose? I had absolutely no idea that lawn mower engines would be this complicated.
Also any chance you can steer me in the right direction as to what alternator to purchase for this engine so that it will be compatible?
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
  • / Husqvarna TYTH20K46 Briggs engine swap wiring issue. HELP!
So you tossed the previous motor out before you replaced it with the new one
why on earth did you do that ?
The alternator & rectifier will set you back around $ 100 US
There are around 20 different alternators used on B & S engines and while it would be simplier to have just 1 or 2 people are too cheap & want the cheapest possible ticket price so engines are made with cheaper electrical systems
I think the lowest cost system will be the # 695466 stator + # 691185 regulator which should be around 9 amps
Quick check shows the pair to be about $ 150 US for genuine
Certified aftermarket ones will be less expensive but you need t get them from a mower shop or dedicated stand alone on line mower parts suppliers
The Prime Line ones were the best aftermarket ones I have ever used , Stens are also OK never used the Rotary ones
Unbranded off Evilpay or Ammozone = garbage .and a lot of them come with bare wires , ie no plug ,
As for wiring
go to Husqvarna and download the parts manual for your mower
The first item will be the wiring diagram
When you have got that & your alternator come back & we will talk about connecting things up
 

foleif

Forum Newbie
Joined
Sep 13, 2022
Threads
1
Messages
4
  • / Husqvarna TYTH20K46 Briggs engine swap wiring issue. HELP!
Simple answer to your question... Ignorance unfortunately. I do appreciate all your help! Thank you!
 
Top