I just found this thread and wanted to post and see if the solution to this problem has been found and verified by it not coming back. My car did the exact same thing yesterday, i.e., guages went out when driving, relay buzzing behind fuse box, got home and shut off, then turned key to start posiiton and nothing happens. I am wondering if it could be a bad harness or is there another relay to look at. From the sounds of it, replacing the buzzing relay is most likely not going to start the car. I have a feeling if I jump started the starter it would probably run, like was done in this thread, but doesn't fix the problem. Please pass on what was learned from this experience so I can figure out what to do as a next step.

THANKS,
John