Rear window defogger

I live in a desert climate and a couple of weeks ago we had some rain for
the first time since buying my '03 Accent in December. With the increased
humidity, the windows fogged up and I had to use the rear window defogger. I
noticed three of the electrical resistance heating elements were not
working. I meant to mark the strips so I could be specific if I took it in
to the dealer. Alas, I forgot. Can the dealer test for this? It's not a big
issue... as long as I remain in a desert climate. But it is something
that's "not right."

 

They should be able to find the ones with the open circuits in them.

 

Thanks. Now I just need to figure out if it's worth my time to take it in to
the dealer. Maybe I'll just wait until there's an additional reason to take
the car in.

 

Went through this with my 02 Elantra already. There is a diagnostic
procedure that the dealer must go through, and the procedure requires them
to reproduce the problem. Therein lies a problem in itself----getting a day
when the dealer can "make" the window fog----if they can't, your car will be
at the dealership until they can----unless you can't or won't leave it there
for the right climate conditions.

By the way, the fix is not simply to repair the elements. The entire rear
window has to be replaced.

 

FerdyPooh wrote:
.... Therein lies a problem in itself----getting a day

A steaming kettle will produce enough moisture to fog a window and watch
the heating grid.

gkw

 

Considering Las Vegas is a desert climate, that could be a long wait! Of
course, one could always create the condition artificially. At least that's
what I was going to do to mark the the bad strips before taking it into the
dearler, but hyundaitech's response led me to believe the dealer would have
a hight-tech method of testing. Maybe not!

Wow, that's incredible!

 

The way I way going to do it was to cool down the window from the outside
with some towels soaked in ice water. Then I was going to take a steam iron
into the passeger compartment and realese a few shots of steam to raise the
relative humidity so there would be water vapor available for condensation.
(I considered a steaming kettle, but thought a steam iron would be safer.)

 

Unless Hyundai has started using embedded grids you do not have to
replace the rear glass to repair broken grids.

All you need to use to find the broken grids is a voltage meter. One
side of the glass is at 12-14 volts and the other is grounded
that 12 volts through the resistance element printed on the glass is
what generates the heat that does the defogging.
To test the grid you first have to determine which side is hot and which
is the grounded side. Easy to do. First turn on the defogger, then take
the meter probes and connect one end to a known ground connection (body
or chassis) then probe one side and watch the meter. If the meter goes
up to 12-14 volts you have the Hot side. Double check by probing the
connection on the other side and it shouldn't go up much at all. Now to
find the breaks. First Connect the meter to the ground connection. Now
starting at the top grid GENTLY slide the other probe from the hot side
to the ground side along the grid. Watch the meter. Normally as you go
across the voltage will drop slightly as you near the grounded side. IF
it suddenly drops to nothing the grid is broken just before that point.
Use a dab of grease marker or tape to mark that spot. Continue down the
grid marking those spots. (a lot of the time they are in a row, like
something hit them or they rubbed on an edge). Now you know where those
breaks are. You may not have them all because they grid could also be
broken between those spots and the ground as well.
NOW if you plan on having a dealer do the repairs you just saved some
labor, BUT if you want to DIY there are a lot of kits available to
repair the grid yourself. The one I recommend for others is made by
Loctite and is part number 765-1460 at NAPA. It has a brush, masking
device, and the repair compound. You just clean the area with alcohol
and then hold the mask over the break and then brush on the compound.
Once it dries your back in business. What I do is coat the known breaks
and then use the tester to see if I have voltage all the way across now.
If you do that grid is done. If you find another break just repeat the
repair process and try again.

 

Great post Steve! I've saved a copy of it in case I should decide to do it
myself. (I doubt I'll do it myself considering the car has less than 3000
miles on it. It's a matter of finding a block of time to waste sitting
around the dealership.)

Thanks!