Rear Window Defroster

[Dr Gonzo]

Ever since I brought the Beast a couple of years ago, the rear window defroster has never worked. Recently while having the rear window repaired I noticed that there are two wires, that were once soldered to something, were not attached to anything but the rear window.

I am guessing that this has something to do with my defroster problem. My question is where do they need to be soldered to?

Thanks

Drew

[Luperman]

On each side of the back glass there are metal strips (vertical strips) solder each wire to the bottom of these strips respectively, you will also need to look for breaks in the horizontal lines ,when/if you find any you can buy a repair kit to fix the breaks , Good luck

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84 Grand Wagoneer 360
86 fiero V-6

[wagdriver]

If you look on the bottum of the window glass you will see where the to wires were soldered. If you have never done any soldering I would suggest that you make friends with some one who can. The wires can be resoldered. Procede as follows when soldering cleanliness if everything. Use a small stainless steel wire brush to clean the pad where the wire was previously soldered, also clean the end of the wire, they are probably corroded at this point. From Radio shack obtain some rosin core solder and soldering paste. Tin the wire by applying some of the soldering paste heating the wire with a soldering iron and adding solder as the wire becomes hot enough for the solder to melt. When the wire is tinned it should be bright and shiny. Inspect the pad on the glass where the wire was attached. After cleaning as mentioned above apply some of the soldering paste to the pad. At this point if there is not much solder on the pad, heat it carefully with the soldering iron, watch the paste when it starts to liquefy add some solder. With that done, you may have to get some one to help you hold the wire in place on top of the pad. Apply the soldering Iron on top of the wire and wait for the solder to melt together, hold the wire in place until the solder solidifies. Then all you have to do is put everthing back together and hook up the wires and see if it works. When you turn the switch on you should measure 12 volts with a multimeter across the the 2 pads you just soldered, if not check for a blown fuse.
Most likely some of the heating elements on the glass are broken, you can tell which one are not working because they will not clear the glass. Best to check these in the early morning, after the dew has fallen. You can get a kit at most any auto parts store to repair these(Locktite makes them)I have found that useing small pieces of scotch tape on either side of the element works better than the guide they supply with the kit and it allows you to maintain the same trace width, so it doesn't look like Magilla Garrilla did the job. Hope this helps. I have done mine and some of the traces need repair now, so I won't be to far behind you. http://www.ifsja.org/ubb/wink.gif

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wagdriver
88 Grand Wagoneer
135k and still going
K&N everything else stock
95 Dodge Ram 2500 360 stone stock

[giddyup]

My defroster was not working and I pulled the window out and took it to 3 different glass shops. None of them would solder it for fear of heating the glass to much and shattering it. I thought about trying it myself and if I broke it calling the insurance company and lying but I did not do that. I ended up just installing it with out the defroster working.

Becareful and let me know how it goes.

[Dr Gonzo]

Is it possible to break the glass by dropping hot solder on it? If it is would it be wiser to just tape it up with some electrical tape? Another glass repair is something that I could do without. Actually any extra repair.

[wagdriver]

It would not be a good idea to just tape the wire in place on the window, that would only create a hot spot where the wire is taped to the window. In reality the defroster is a pretty hight current system and if you loose current to it at the connections you won't get the efficiency needed to operate the defroster. The glass is pretty resilient, you don't hold the soldering iron on the wire and pads any longer than is necessary to melt the solder. One other thing you can do is let the window warm in the sun for a period of time this will reduce the thermal stress when the soldering is done. http://www.ifsja.org/ubb/wink.gif

Actually one of the problems is that the glass acts as a huge heat sink and robs the solder area of heat, you need to use a pretty good sized iron to do the job. They do it at the factory all the time granted they probably have ideal conditions to do it in. I did mine in my back yard with out any special preparations other than cleaning as stated above.


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wagdriver
88 Grand Wagoneer
135k and still going
K&N everything else stock
95 Dodge Ram 2500 360 stone stock



[This message has been edited by wagdriver (edited May 30, 2001).]