It looks like you are determined to do this the hardest way possible.
You really need a circuit diagram other wise it is just a guessing game.
Now for starters I doubt you are really getting a 3.2A load.
Most lawnmower batteries are between 20 to 30 Amp Hours.
So if you had a 3A load the battery would go from fully charged to dead flat in 7 to 10 hours not over 3 weeks.
30 Amp Hours means exactly what it says.
Any combination of Amps x time ( hours ) that equals 30 ( 15 x 2 , 5 x 6 , 3 x 10 etc etc etc )
If you had a 3A load you would see a large spark whenever you connect or disconnect one of the battery terminals.
This is one method I use for chasing phantom loads, much more reliable than trying to use a multimeter and in particular the modern auto ranging digital meters.
I jack the mower up , put it on jack stands then unplug & replug each switch till one of them flashing at me.
You can download the circuit diagram form Simplicity by going to this link
https://www.simplicitymfg.com/na/en_us/support/manuals.html
Click on the tractor then type in your model number in the pop up box.
Download all 3 manuals that apply to your tractor, Wiring, operators & parts.
On page 49 of the parts book you will see the actual loom as it is installed on your mower
The 3 circuit diagrams are all the same.
The wires that are shown in colour are the ones that are applicable to the task printed underneath, starting, charging & stopping to make it easier for people who get confused by wiring diagrams to understand what is connected to what.
I seem to remember twice suggesting that you check the rectifier.
By check I specifically mean for you to unplug the violet wire , not check with the dealer to see what he thinks
If you want support from the forum it is a 2 way thing.
We ask you to do things then wait for you to post the results.
Based upon what your response is we suggest further testing or replacing parts, that is how it works.
Others look at what you are being asked to do and if they see a problem they chime in and we sort it out.
If you look at both the wiring diagram in the parts book and the circuit diagram on the wiring pages you will see that there is only 1 wire connected to the + on the battery.
that wire goes to the solenoid then to the breaker then to the ignition switch where according to the box in the bottom right corner it connects to the B wire and when turned off, nothing else.
SO test no 1 is to back test the plug on the ignition switch to confirm you have 12V between the B terminal and ground and no VOLTAGE readings between any other terminal and ground while the ignition is turned off.
Test 2 is to verify the connections for the on position the same way
Test 3 is to check the start position but you might need a 3rd hand to do that,
Do this and tell me what you found.