[Vwdiesel] how to test rear window defrost lines

[Bryan Belman]

I have the back window out of my van as rust needed to be addressed under the rubber, that is done.
I know the rear defrost lines, now almost 30 years old, did not work well.
I removed the tint from the grass I had put on years ago, that was tough

Now, having trouble finding a good way to test, ohm meter does not seem to be the way and I do now want to hook a battery directly up to the glass, I do not think that is a good idea.

I was hoping to fix the breaks with the fix kit I have and then put new tint on and put back in van, but ohm testing shows from .007 to .003 in various  places and only .001 when within 2 inches of each probe on the defrost line.

Does anyone have a good idea or do I need to put in back in van and put the tint on later after I find the breaks under real weather conditions.
??
 
Bryan Belman, Pt. Pleasant, NJ
04 Jetta Wagon TDI PD, 100hp, 5sp -- running :<)
92 Jetta 1.6 Eco-Turbo Diesel, 5sp -- running :<)
82 Diesel Westy 1.9NA -- running :<)
70 Type 1 stock Elm Green Beetle -- Under Restoration :-)