@
TheDurk
@
pavelvoivoda
Success! I wired in my switch as per Pavel's idea. Pretty easy to get to the wires once the fuse block was pulled out.
I tried a 5A fuse and it worked when running a single window but blew when running two. So I upped it to a 10A which was happy with 2 windows at a time.
Thanks again for the advice and ideas, guys!