I have seen some posts in relation to this but in searching I haven't seen a good explanation of the solution. Currently my rear window defroster only works at the top 1/4 of the window. I inspected the defroster and there doesn't seem to be any breaks in the tape in the window. How easy is it to get to the connector for this and where is it located?

 

its a grid fed on each side with all lines in parallel.
if some dont work and others do, some are open. probably tiny scratches.
ive heard there are fixes but dont know how.
like conductive cement.??
google it!

 

I searched the repair manual for some guidance and drew a blank. The next step is to tear apart the interior trim and find the connections and go from there. Just looking to see if anyone has already conquered this problem before.

 

since part works,the 2 connections are ok, its open elements in the grid

 

As stated if some work then it is not the connection points. You probably have small scratches somewhere in the grid, depending on how small they may be difficult to find. They do make a copper based paint on type cement stuff to fix this. It comes in a small bottle with a brush to put it on the b spot and act as a jumper to allow the flow of current. If you find the breaks I'd suggest getting some fine line take tape by 3m that a body shop would use to mask the line otherwise you'll end up with an ugly glob.

Not positive if it would work to help finding the break and someone may be able to chime in but in theory you could turn on the defroster and take a multimeter and touch the leads along the grid to narrow down the location where there is no continuity, just be careful not to scratch any more breaks into the grid lines. Again I'm not positive if it will work but it might and if so make it easier tracking down the breaks.

 

OK, bought the $6 tester and found an area about 4" wide across almost all lines that although it appears to look OK, has been worn away, probably from the previous owner loading something in the back that was rubbing up against the window. I bought the repair kit for $17 at Advanced Auto and have used detail tape to outline the grids. After applying 2 coats and using up all the metallic epoxy paint its now curing for 24hrs. I have my fingers crossed.

 

Check back in and let us know how it works.

 

Good luck. Sounds like you went about everything in the correct way. As long as you cleaned it well and got good adhesion you should be good to go.

 

OK, so the process works. I have some minor touch ups to do but the grid for the most part is conducting and heating up. Doesn't look the best but it does work. Now the next thing to solve is what to coat the newly repaired area with. The finish of the repair is rough textured and anything rubbing up against it will most likely wear on it and create the same problem. I'm thinking some kind of clear laquer or maybe clear nail polish.