as usual, most of my rear defrost strips have died... is it easier to replace them individually or get the whole glass from a wrecker... and if from a wrecker, how do i test to make sure those ones all work?

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there's no replacement for displacement

 

Well you have a couple of choices. One the reason most of the strips "die" is because there are tiny breaks in the lines. You can repair these breaks with a $10 kit available at local auto stores.

If they are completely stipped like when you pull tint off the back hatch glass, then they are pretty much destoyed and trust me in the end it will be cheaper just to just replace the hatch. I got a used hatch with working defrost for $100, to buy enough repair kits to do all the grid lines over would cost more than that and looks like sh**.

Then there are grid line kits from places like JC Whitney. Don't bother. They don't fit right and also look like sh**, because you can't mount them over your old ones and your whole hatch has mismatched thin copper lines and thick silver lines (Whitney's). But this kit should be okay for people who originally did not have a defroster.

Now, how to test. Before you buy a new hatch (which will require at least 2 other friends to help you install and you are going to have to take your deck lid and mount it on the new glass or have the new one painted to match which is a PITA) test your lines now and try to just patch the little breaks.

This is from my 83 TA factory manual, but should apply to all thirdgens.

To locate inoperative grid lines:
Turn on the defroster and get a DC voltmeter.
1) Ground one test lamp (voltmeter) lead and lightly touch the other lead to each grid line.
2) If test lamp shows full brilliance (full voltage) at BOTH ends of grid lines, check for a loose ground wire.
3) All gridlines must be tested in two places to eliminate the possibilty of bridging a break
4) For best results test each gridline a few inches to either side of the glass vertical centerline
5) To test a specific line, Place the lead on the LEFT FEED BUS BAR (The wide vertical strip attached to power, driver's side) and slowly move lead to the RIGHT GROUND BUS BAR (attached to ground, passenger side)
6) Be aware that the brilliance of you test light SHOULD decrease as you move from Left to Right, (driver's to passenger). (Increase in resistance, less juice, the further along the line you move)
The diagram in the manual shows the window divided into 5 equal vertical sections. The sections starting behind the driver have full brilliance (voltage), then 3/4, then 1/2, 1/4, and finally the last section behind the passenger SHOULD have ZERO brilliance.

If there are broken lines, then you will have full voltage, starting from the left, until you hit the break in the line, and then Zero brilliance (from the break to the ground)
I hope this helps. I'll see if I can post a pic.

 

You can usually find the breaks by looking for them. The next time your car gets foggy & you notice which ones do not work, take a small piece of tape & mark which ones do not work, then that will give you a place to start. Then inspect those lines.

Nightcruzer's method will work perfectly well though...

John

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