Rear Window Defogger: Testing: Grid
- Using a DC voltmeter with a 0-15 volt range, contact bus bar connecting grid lines on right (Feed) side of glass with negative lead of voltmeter. Contact left bus bar with positive lead. Turn ignition and control switches "ON". Voltmeter should read 10-14 volts. Lower voltage indicates a poor ground. With negative lead, contact a good ground. Voltage reading should not change.
- Contact negative lead to left side bus bar and with positive lead, touch each grid line at midpoint. A 6 volt reading indicates line is good. A reading of 0 volts indicates a break in line between midpoint and right bus bar. A 10-14 volt reading indicates a break between midpoint and left bus bar. Move positive lead toward break and voltage will change when break is crossed.
Courtesy of CHRYSLER GROUP, LLC