Well it sure as heck sounds like your climate control unit is the problem. Probably an internal short somewhere. If you were an electronics/techy kind of guy you might dig into the thing and see if you can locate any shorts or burnt up connections. Electrical gremlins are tricky in any case and your best bet is to just replace it. You should be relieved that it was such an easy problem to pinpoint. Some of us (myself included) have on-going electrical issues that we have learned to live with. Personally, if my headlights are not on, every time I put on the blinker all of the lights on my climate control unit flash along with the blinker, as do my lower running lights in the rear. I think it was caused when the PO installed LED signal/tail lights. I have yet to pinpoint the problem so I just live with it. lol