Test B: No Communication With Lighting Control Module
- Turn ignition off. Disconnect 16-pin Lighting Control Module (LCM) harness connector C2029. LCM is located behind left side of instrument panel. Turn ignition switch to ON position. Measure voltage between ground and LCM harness connector C2029 terminals No. 6 (Tan/White wire) and No. 11 (Light Green/Yellow wire). See Fig 1
. If more than 10 volts exists at both terminals, go to next step. If less than 10 volts exists and either terminal, repair appropriate power distribution circuit. See POWER DISTRIBUTION article in WIRING DIAGRAMS.
- Turn ignition switch to LOCK position. Measure resistance between ground and LCM harness connector C2029 terminals No. 4 and 9 (both Black wires). If either resistance is are 5 ohms or more, repair open on appropriate Black wire(s). Recheck system operation. If both resistances are less than 5 ohms, repair module communications problem. See MODULE COMMUNICATIONS NETWORK - CROWN VICTORIA & GRAND MARQUIS article.
Courtesy of FORD MOTOR CO.