Kohler to briggs help

Looking to go from a 5 wire CV15 kohler to a 4 wire 28n707 15hp briggs on a LT1538 husqvarna  (similar to LT1000 craftsman) Does anyone know of a location for wiring diagrams online?
On the tractor I have yellow, black, orange, red, blue
On the motor I have yellow, red and black/red white.

I also have a parts tractor that had a briggs
3 wire

I'll do my best to help, I've put a CV16S where a Briggs Flathead used to live and have a Toro with a 28q series Briggs, I gutted the whole interlock system from that tractor, I've also wired several from scratch.

Unfortunately I can't start digging too much tonight as it's late and I need to go to sleep but I'll look into it more tomorrow after work and see if I can find your tractor manual, we'll need it for the wiring diagram.

Keep in mind all the motor needs to run electrically is 12 volts to the fuel bowl solenoid if equipped (which it probably is) and the starter wire. It should have 1 wire (with inline diode) to charge the battery, 1 wire for the headlights if the tractor had them, 1 kill wire and I think that about covers it!

If this tractor is going to be strictly a toy I highly recommend removing all the wiring loom from the wires so you can trace them all, removing the complete interlock because it will cause you nothing but headaches. With the tractor I gutted the interlock from I had to add a wire from START to the starter solenoid and a 5 pin relay (NC/pin 87a) to keep the kill feature working at the key switch BUT that Toro had some silly kill relay system unlike anything I've ever seen plus a interlock "module".

Really hard to do this stuff without the tractor in front of me and a multimeter in hand but step by step you'll get there!

**Edit** I found the manual pretty quick (and from a trusted source) so I'll be able to review it tomorrow, here's a link to download it.
https://www.manualslib.com/manual/74421/Husqvarna-Lt1538.html

Basic as possible is great. I can clip the solenoid and forget the safety /interlock

The engine i was told came from a white( mtd?) Older split harness

Maybe this can help a bit?  Jump to 29 minutes in.

I have simplified the process since these tips


Negative battery terminal grounded to frame
Positive runs to factory relay with two prongs
Positive continues after relay to starter
Two wires from engine. Red with diod and black for kill.

This is what I came up with watching fearless fronts video

I made another edit. I'm gonna have to get a test light to see if the plug on the relay gets power. Then the second plug would be power beyond with the key on which I eliminated

I used part of my husky harness and one wire from my LT1000 parts frame

Still some work left

Looks like you're moving along nicely, good work!