8 cylinder front engine iconic vehicle
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By captainOCD
#88324
As requested, more details of my repair/replacement of the defroster grid lines on the back window.

My defroster lines got hashed during removal of some old tint that was on the car when I got it. I tried my best at the time to save them, but maybe half of the lines worked at best.

A buddy of mine came across this site a few weeks ago. https://frostfighter.com/clear-view-order-guide.htm Turns out they sell defrost grids both to add to cars that didn't have them and to repair grids that are damaged.

Looking at their site and measuring the grids on the back window I wound up settling on 2 of their 1210-2740-STK (12.5" height x 27-40" width) setups. Conveniently each of their grids (at least in this size) were 10 lines like the factory grids. Be sure to get the one that doesn't come with the wiring and controller (no point it paying for that stuff). It came to right around $115 shipped for me.



I wanted to lay these new lines directly over top of the existing lines to keep things as neat as possible. This required scraping off all of the remaining defroster lines (and remaining tint adhesive) with a razor blade. There's still going to be some of the line left that's the backing I suppose, but the resistive lines are all gone now:

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The lines in the kit do come spaced out evenly with the intent being that you'll apply the entire sheet of 5 lines at a time. The spacing is something like an inch and a quarter though.

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To get the new lines to line up right with the old lines I had to carefully cut the lines apart from the sheet. Then you can carefully lay each line down overtop of the old lines. Be sure to leave a couple inches extra at each end.

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The new lines are good bit thicker than the original lines, but not much you can do about that. It doesn't seem obstructive in the mirror.

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After getting all the lines laid down the backing can be peeled off carefully. Again, be sure to leave a couple inches of the lines at each end.

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After laying down the lines the buss bars (and the foam tape holding them down) can be applied. This is where you need to be cognizant of where the connections for the grid are going to wind up. Effectively they have 2 lines run in parallel with each other, serpentining back and forth a couple times. This leaves you with one terminal towards the bottom on one side, and one towards the top on the other. I chose to place the busses such that the terminals were towards the bottom were on the left/driver side of the car. The power wires from the original grids will need extended to reach them on whichever side they are towards the bottom on.

Also worth noting that while I didn't change anything electrically about how they want you to wire these grids, I did put the lines a few mm closer together which over the whole grid did shorten it maybe an inch or so. To make the buss bars (and their covers) fit a bit better I did have to trim them with some tin snips.

Another thing that you need to think about is reattaching the side trim panels. The factory grid has the terminals lay flat and come up under the trim to be plugged onto. These grids have the terminals face lengthways along the side of the window. This can cause some difficultly getting the side panels to sit nicely back on the hatch. I'm still scheming up a way to correct this with mine.

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After the buss bars go on you fold the grid wires over top of the buss bars and tape them down to hold them in place. Then place the covers on the buss bars and trim the excess grid that was folded over. (I forgot to get a picture of the intermediate step, but they cover it well in their instructions).

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I used some insulated spade terminals and some 12 gauge wire to make little extensions for the factory wires on the driver's side. You could do this some other way, I just didn't want to butcher the factory wiring in case I would replace the window some day.

You can see here what I was referring to earlier about the connections for the grid possibly interfering with the hatch trim panels:

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I also snuck the top grid in for the photo above. The only difference there compared to the lower grid was that I had to take the 3rd brake light off and carefully remove the trim/mounting bracket for it from the window to lay the grid, then readhere the trim to the window. I tried bending the grid around the outside edge of the light and laying it down behind the black masking, but I couldn't get it to lay down nice. Fortunately I didn't damage the line trying.


Here's the final view from the outside.

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And from the inside

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I don't have any good action shots of them, but I have used them once so far. On low power they quickly got rid of some fog/dew that was on the windows early one morning. I don't really know what the original grid performed like for comparison though. I didn't measure what the resistance across the grids are or anything, but I'd be happy to do that to get an idea of how much current these will draw compared to the original ones.

Either way, even though I hardly have needed the defroster in this car, it is nice to know it's there if it is needed.
worf, SeanR, Bertrand Daoust and 1 others liked this
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By jschiller
#88446
Nicely done and nicely documented. This thread will be a keeper.
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