[1986nate]

Let me update this. First I will clarify that I did in fact do the differential swap on the transmission, helped bolt it up but figured Joe could handle the rest since he's done a couple trans swaps already. Thought it would be no big deal.

So in more detail, from the sounds of it, The car went from when he first started it up and took it for a test drive, everything worked fine but the speedometer. Tach worked fine, dummy lights all worked as they should, etc.
When he stopped and took out the FWD fuse, he lost tach, dummy lights, pwr windows and sunroof, climate control and in the time that I was able to come back over, the radio had worked but then stopped working. The backlighting on the gauge cluster and climate control still all work, however not the button on the end of the stalk that lights the clock and other stuff back to full brightness with the lights on. I know about the breaker under the driver seat but typically that knocks out the power seat as well but that still works as it should. If it can kill the sunroof and windows separate from the seat, that would be valuable information.

There were no blown fuses and inserting the FWD fuse back in made no change except that might have caused the radio to stop working when we plugged it in and unplugged it a little later. (Didn't notice the change in radio function right away as the volume was off and was not something of focus until it was not working. Also, all grounds appear to be fine. I was not able to look too deep into anything as it was very late, it was dark, and I was tired from a long day of doing other work as well. Also, I'll be the first to admit that I hate electrical issues and advised Joe to come on here as there are a few here that are well versed in the wiring and electronics of the SVX. Hopefully this can clear some things up and help get some more solid leads for him to check out.

Edit: Also advised Joe to leave the speedo wires unplugged for the time being and taped up so they cannot short out against each other. I do have another harness with connector from the junkyard for him to splice in that I will be giving him tomorrow so that this can't be an issue.