Turn signals not working, blowing fuse

OK. So it is the stop light and turn signal fuse.
The car starts fine without that fuse.
I was trying to narrow down what didn't work when Fuse 2 opened.
Now knowing its fuse 3, the program (factory info) still makes sense.
And just as a heads up, the wiring diagram shows the stop light switch on fuse 4, which makes sense. Fuse 4 is always hot, key on or off.

We know:
Fuse 3 opens with Turn signal off, radio off, heater off.
Therefore it has to be shorting between the fuse and those switches. Right?

I'd be tempted to go to the flasher unit first. See what it looks like and if nothing obvious, disconnect it and see if then probe for a ground on each side of the flasher connector.

Do have the shop diagram?
I know its a pain to read but its helpful in showing what connects to what.