hogpie wrote:

Can anyone tell me how to test a rear window defroster

You can use a regular 12V test light by grounding the one end to the chasis and runing the pointer over the lines ( with the switch ON of course)inside on the window. A good connection will make the light work. If this defroster is original, chances are it is just not conducting from years of baking in the sun and or a broken line in series.

First check the switch and fuse to see it you are getting and sending voltage to and through the switch in the dash. Next check at the wire lead at the glass. If you got juice ther but not in the grid on the window, you need a new grid. They are made as after maket parts and can be found most anywhere.

good luck