Repair Defroster Grid Breaks
If the defroster clears only part of the rear window, it’s
usually a sign of a broken horizontal grid line. The first step
in repairing this type of damage is to locate the break by
visual inspection. The smallest break or crack can cause the
defroster to fail.
If the break
in the defroster grid is not obvious after close visual
inspection, use a volt meter or 12 volt lamp to help locate the
damage. Turn on the defroster and touch one meter lead to each of
the wide vertical bars along the sides of the defroster. The reading
should be between 12 and 14 volts. If the volt meter shows a negative
reading, reverse the leads.
Now take readings at various places along the
horizontal lines of the grid to isolate the break. When you pass
over the break, the reading will change sharply.
Simple voltmeter alternative
If you do not have a volt meter you can use the
Fighter Test Lamp. This simple trouble lamp makes it easy to
find the breaks in defroster grid and features a 12 volt lamp,
alligator clip, soft probe and long wire leads.
Once a break or breaks in the defroster grid
has been located, it’s time to consider how to repair the problem.
Repairing Defroster Grids
The NEW highly conductive 2120 Frost Fighter material is
designed to repair grid damage. Use the tape to precisely mask off the damaged area of the defroster. There may
be more than one break in the grid so locate all the damage before
proceeding. The grid kit can repair breaks up to five inches.
After the damaged areas have been located and
masked, apply the repair material using the cap brush.
Frost Fighter grid repair kits use a highly conductive silver polymer
repair compound. This polymer bonds aggressively to glass and provides
maximum electrical conductivity.
Removing the masking tape while the conductive repair coating is
still wet for uniform highly conductive defroster repair.
Cure to finish repair
Allow the conductive repair coating to dry for ten minutes at
temperatures above 70F (21C) degrees. If the temperature is
below this use a heat source to warm the repair area for the ten
Now turn on the defroster. The
heat from the defroster to cures the repair in about 10
minutes. The defroster can be used at this point.
The conductor is color matched
to the reddish brown colors used in automotive defrosters for nearly
Preview Grid Kit instruction sheet
Adobe PDF (300 Kb)