Power Window System: Diagnosis GMC Envoy I

TROUBLE SHOOTING

Before proceeding to SYSTEM TESTS , perform the following visual inspections

1. Check condition of POWER WINDOW CIRCUIT BREAKER (30-amp), located in I/P fuse box or Body Bussed Electrical Center. If fuse is open, locate and repair cause of overload. Replace if damaged.
2. Check for mechanical failures or binding linkage.
3. If express down feature does not work, but window moves down with each switch depression, replace left window switch.
4. Check for broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. These circuits may be intermittent or resistive when loaded. Check by monitoring voltage drop with system under load.
5. Check for proper installation of aftermarket electronic equipment.