Welcome to our site . . . I personally don't have any information on your issue, except to say that it does definately sound like an electrical problem with one single cause for all of your guage issues.
The temp guage is definately not reading correctly, as is true for the others.
Try these:
http://apollo.pacificweb.net/~sketch/osg/osg.html
http://www.hands-on.org/pfkb/
http://www.fierotech.com/
I found these few sites while scouring the web for information to help you. Unfortunately I found nothing, and I can not vouch for the sites that I posted . . . I just hope that you'll find what you're after . . .