Hi Stedy,
If you look on Aminet you can find a package called "PCFloppy2Amiga".
Although for external drives the author had the same problem with the diskchange and he goes into great detail about why and how he solved it.
Just wondering if it would be a help maybe.
EDIT: You are correct in that it has to latch high.
EDIT: EDIT: MK2
Nearly all drives are set for DC, hence moving either a jumper or SMD link on the modded drives. I'm sure it's pin 2 on a floppy drive. If it is it should be as simple as reconnecting it.