Yukon 2WD V8-393 6.5L DSL Turbo VIN S (1995)
Heated Glass Element: Diagnostic Trouble Code Tests and Associated Procedures
Circuit Operation
With the Ignition Switch in RUN, voltage is supplied to the Rear Defogger Switch. When the Rear Defogger Switch is moved to the ON position the
contact closes, which provides voltage to the ON Indicator and the Rear Defogger. The rear window will become warm to remove fog from the surface
of the window.
The contact in the Rear Defogger Switch will remain closed until the Rear Defogger Switch is turned OFF or the timer cycle is complete.
The Timer also shuts OFF anytime the Rear Defogger Control ON-OFF Switch is depressed to OFF.
Troubleshooting Hints
1. Check to see that REAR DEFOG and HTR A/C Fuses are not open. If open, LOCATE and REPAIR source of overload, then REPLACE fuse(s).
2. Check that grounds G200 and G400 are clean and tight.
3. Check that Rear Defogger Grid(s) is continuous and free from damage.
4. If vehicle is not equipped with a liftgate, then check that LH/RH Door Contact Switch contacts are clean and free from obstructions.
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Check for a broken (or partially broken) wire inside of the insulation which could cause system malfunction but prove "GOOD" in a
continuity/voltage check with a system disconnected. These circuits may be intermittent or resistive when loaded, and if possible, should be
checked by monitoring for a voltage drop with the system operational (under load). Check for proper installation of aftermarket electronic
equipment which may affect the integrity of other systems (Refer "Troubleshooting Procedures," ). See: Diagrams/Diagnostic Aids
