Mechanics

CHEVY POWER WINDOWS

1999 Chevrolet Silverado

Electrical problem
1999 Chevy Silverado V8 Four Wheel Drive Automatic 100000 miles

Driver side window is down. It will only go up an inch or so, then it stops.
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Trich3838
July 12, 2009.



PRELIMINARY INSPECTION 1. Check condition of POWER WINDOW circuit breaker, located in Left Bussed Electrical Center (LBEC). See COMPONENT LOCATIONS. If circuit breaker is open, locate and repair cause of overload. Replace if damaged. 2. Check IGN B maxifuse (50-amp), located in Left Bussed Electrical Center (LBEC). If fuse is blown, locate and repair source of overload. Replace fuse. 3. Check RAP maxifuse (50-amp), located in Underhood Bussed Electrical Center (UBEC). If fuse is blown, locate and repair source of overload. Replace fuse. 4. Check for mechanical failures or binding linkage. 5. If express down feature does not work, but window moves down with each switch depression, replace left window switch. 6. 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. 7. Check for proper installation of aftermarket electronic equipment. If problem still exists, repair by appropriate symptom. See SYMPTOM INDEX table under SYSTEM TESTS.
TEST 2: LEFT FRONT WINDOW INOPERATIVE 1. Disconnect master switch assembly connectors C1 and C2. Turn ignition switch to RUN position. Using a test light connected to ground, backprobe master switch assembly connector C2 terminal " F" (Dark Green wire). If test light illuminates, go to step 3. If test light does not illuminate, go to next step. 2. Repair open in Dark Green wire between master switch assembly connector C2 terminal " F" and Left Bussed Electrical Center (LBEC) connector C4 terminal " K". See WIRING DIAGRAMS. 3. Ensure left front window switch on master switch assembly is in neutral position. Connect a test light between battery voltage and master switch assembly connector C1 terminal " M" (Black wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 6. 4. Connect master switch assembly connectors C1 and C2. Disconnect left power window motor connector. Ensure ignition switch is in RUN position. Connect a test light between left power window motor connector terminals " A" (Dark Blue wire) and " B" (Brown wire). Observe test light while operating left front window switch on master switch assembly to UP and DOWN positions. If test light illuminates in both positions, go to next step. If test light does not illuminate in both positions, go to step 7. 5. Replace left power window motor. See WINDOW MOTOR & REGULATOR under REMOVAL & INSTALLATION. 6. Repair open in Black wire between ground connection G203 and master switch assembly connector C1 terminal " M". See WIRING DIAGRAMS and COMPONENT LOCATIONS. 7. Using a test light, backprobe between master switch assembly connector C2 terminals " A" (Dark Blue wire) and " M" (Brown wire). Observe test light while operating left front window switch on master switch assembly to UP and DOWN positions. If test light illuminates in both positions, go to next step. If test light does not illuminate in both positions, go to step 9. 8. Check for open in Dark Blue wire between master switch assembly connector C2 terminal " A" and left front window motor connector terminal " A". Check for open in Brown wire between master switch assembly connector C2 terminal " M" and left front window motor connector terminal " B". See WIRING DIAGRAMS. Repair as necessary and retest system. 9. Replace master switch assembly. See WINDOW SWITCH under REMOVAL & INSTALLATION.
A common problem is the wires break where they pass from door to the body, right where they bend.

Merlin2021
Jul 12, 2009.