Alright, many apologies for a non-F150 question in this forum. But I'm out of ideas and I need to call upon the expertise of my fellow F150 owners.

My fiance owns a 2004 Alero and the rear window defroster has quit working. The light comes on when you hit the button but the defrost doesn't get hot...

I went through the normal progression

FUSE - OK... checked it a couple times now
RELAY - not sure, so I replaced it with a new one.

So yesterday I got in the back with my multimeter and checked the connections to the grid. When I first checked them it read 0 volts. So I pulled off the connectors (thinking maybe it was a bad connection) and it read 12 volts. So I put it back together and it read 0 volts.

After doing this several times, I came to the conclusion that once you hook it up there is not enough current so both sides of the grid read 0 volts. Does this make any sense? What do I do?

Any advice would be much appreciated. THANKS!

 

alright... after a couple hours of searching I might have found my own answer... there is an "antenna buffer module" by the rear window that shorts out and causes the defroster to quit working. Some people find a broken connector that can be soldered... hopefully I can find that too. Otherwise we'll have to replace that module.

(the Alero has its antenna on the rear window... so part of the defrost stips are also the antenna)

Thanks for reading...

 

it sounds to me as though you have already solved your own problem.

you have 12v to the connectors at each side of the window when you remove them from the glass. when you place the connectors back on the window are you sure you are able to get a solid connection to it with the meter?

i would first suggest checking the grid and seeing if you have a completed circuit from one side of the window to the other. you can try the audio continuity tester on your meter but you may have to resort to the ohm function if there is to much resistance. (that why it heats up in the first place.) you should be able to just trace the probe along the grid until you find the break in it.

if you do find a break:
http://www.frostfighter.com/

edit: it took me 20 mins to write this after throughly researching it so im going to leave it here anyway

 

great link, thanks!

Hopefully I can just solder a connection in that box... but if I break anything in the process I'll be coming back to get parts off that site.