That is why you need a circuit diagram
And we need one so we can tell you the pink& purple
wire should show 12V then you are naked on the bonnet.
You will find it at the back of the parts book
To get the right parts book you need to use the model number off the tag under the seat.
IT will start with 13 or 14
We also need that number so we can also look up the right circuit diagram
As for the seat switch it is a Normally closed switch
If you take the plug out a hidden contact closes all wires together so you can not start nor run with the seat switch unplugged.
Thank the Face Book Fools & U-tube "heros" for that complication.
The red
wire with the fuse in it will go up to the B terminal on the key switch ( B = Battery )
So the next step is to pull the plug off from behind the switch & check if you have 12 V there.
It is always best to pull the fuse out of the holder & replace it.
Blade fuses can look good even if they have blown.
Did you clean BOTH ends of the 2 battery cables ?
Most common fault is a loose or corroded ground connection .
The brake switch is either under the foot board or under the dash
The PTO switch is of course also under the dash
And that is all you have
Brake, Seat & PTO it is a simple
system.