Down by your left foot, driverside, is a big grey box with a single bolt thru the middle, that box is where the harness comes in from the engine compartment, it's acutally a big plug and the center bolt holds it together. On my 98 I had the pro9blem with dead gauges, CE, Airbag, odometer stops, etc. When I was wiring my fogs in with the factory kit I noticed that this 'plug' was only held together by friction, the bolt had backed all the way out. I remember it was a SOB to get a socket on and used up every 1/4" extension and two universals I had in 3 tool boxes. In my case that pretty well fixed it. I did take it apart and sprayed it out with some cleaner then put it back together.
Also make sure your brake master cylinder is not leaking or if it has been replaced check the bundle of wires underneath it, if brake fluid leaked on the wires it might have eaten them up and that part of the harness is a real PIA to fix..