Electronic gremlins

[m35a1 at juno.com]

Hello list.
I have been getting grief from my '90 V-8 Quattro in the electronics area.
I followed the thread about the load reduction relay causing similar problems but have not been able to locate this device to check it.
Problem(s):
Intermittantly, and with no reason or pattern: 
1. the fuel gauge and temp gauge will not come on. The seatbelt light will then begin to blink and the gauges will flutter while the seatbelt light is blinking 'on', then the belt light will go out and the gauges will work.
2. the speedo will not register, then suddenly come on.
3. the oil pressure indicator on the 'systems status' light will come on, even tho there is sufficient oil and the gauge has not gone below 1.8.
4. the status light will show a bad bulb. when I check, the left rear tailights are out. Flipping the light switch off then on again corrects this situation.
I had a/c condensate leaking into the cab. I cleaned and re-routed the drain line and solved that problem. There had been condensation on the relays on the pass. floor. I removed each of them and dried them out, then drove for about a week with the carpet removed to let the area dry out.
A separate matter: I had removed the steering wheel to repair the windshield washer switch. In the process, I had the ignition switch on with the airbag disconnected (which I've learned is a no-no). The airbag light is now on constantly. 
Anyone offer any advice or instruction regarding the gremlins or the airbag light?
Thanx
Ken