What was found
WITH APU OPERATING AND AVIONICS SWITCH ON, NOTICED A BURNING ODOR, THEN RED X'S ON BOTH SIDES OF NR 1 PFD, A NR 1 ADC FAIL MESSAGE. PULLED NR 1 ADC CB, ODOR CEASED. TROUBLESHOT TO PILOTS LT RUDDER PEDAL CHAFING ON AVIONICS WIRE BUNDLE. REPAIRED WIRES AND REPOSITIONED WIRES FOR PROPER CLEARANCE. OPS CHECKS OF AVIONICS SYS NORMAL. WORK PERFORMED IAW MM 20-21-03 AND 34-11-08.