2006 GT. Rear defroster only works in one line on the back window, but none of the others. I did check voltage to be about 11V from one side to the other on multiple lines Very weird. Photo attached shows the one defroster line working. There is window tint previously removed, and redone, which I heard can damage the lines.

 

Removing the window tint likely caused a small break in the line. It can be repaired with various kits but of course you have to remove the window tint to do the repair.

 

I guess I don't understand. There is around 20 "lines", and they are connected on both sides of the windshield, right?

 

If there is a break along the line it won't defog because it doesn't send the current across. Taking the film off you caused a break or several breaks along the line. The only way to repair it is to look at each line from end to end and find where it has a break. Then use the kit to bridge the gap.

Since one of your lines is working that says it is a problem along the line itself and not a problem with the defogger. You will find voltage on each end as you did because there is current going up the side. It just isn't going across on each line.

 

Is this something that a tinter should know about and know how to avoid? Should I contact him about warranty or quality concerns?

 

I would think that someone doing window tint for a living would be aware of the potential to cause a break in the lines while removing tint. It seems like he would have said something about the potential - maybe it is buried in your paperwork.

Whether he offered you a warranty is between the two of you.