rear window defroster

[e]

Can anyone tell me if there is a way to repair a rear window defroster.
There are 3 or 4 line on it that no longer work.
Thanks in advance

 

[BBB]

You might have some success with the conductive paint used to repair
broken traces in printed wiring boards. You might find this at Radio
Shack, but you will probably have to go to a more specialized
electronics supply company. I know that Active Electronics has stores
in major cities in Canada. It might be available by mail from places
like Digikey or Jameco.

You will have to locate the exact place where the line is broken, clean
it carefully with alcohol, use a fine-tipped brush, cram the paint into
the slot, and cross your fingers. If you have an ohmmeter, you could
connect it across the window and watch it as you're applying the paint
to see if you are making a difference.

Assuming success, you can trim off the excess paint with a razor blade
after the paint dries. Cut right next to the line and scrape outward so
as not to disturb the connection. You will probably never get it to
look as thin as the original line, but consider yourself very lucky if
you get this far.

 

[John]

Most autoparts places will sell the conductive "paint" with small brush and
thin-line template to repair this. The ohmmeter suggestion in the post
above is best to narrow down where the breaks are. Without the ohmmeter you
may have to follow each line with a magnifying glass to see the cracks to
repair. Sounds funny but it works, just takes more time.

 

[BBB]

You'd probably need a pin to get far enough down into the glass to
actually touch the conductive material. You'd have to be pretty careful
not to further damage the conductor in the process. You'd be looking
for a small change in resistance due to the effect of the other (intact)
lines that are all connected in parallel.

What I had in mind was using the ohmmeter across the entire window to
detect a drop in the total resistance of all the parallel lines while
applying the conductive paint, providing evidence that you had
successfully bridged a gap.