[net.auto.tech] More on '81 Malibu rear defogger

jwp@uwmacc.UUCP (Jeffrey W Percival) (11/25/85)

In response to some suggestions, I did some additional troubleshooting.
There are two metal containers plugged into the fuse box, one a little
larger than a regular flat two-prong fuse, the other the size of half
a pack of cigarettes.  The small one is stamped "30A 12V" and I assume
it is the fuse for the defogger.  My meter showed near-zero resistance
between its contacts.  The larger metal box is stamped "10/5 MIN" and
I assume that this is the relay/timer mechanism.  I took the can off,
and exposed the relay.  Contacts looked good, and the relay was observed
to work when I cycled the dash defogger switch.  I unplugged the relay
box, and with a volt meter observed that a potential of 12 volts was
indeed being presented at the socket into which the relay is plugged.
So there.

I think now that there are two alternatives left.  Either
a broken wire in the car's interior, or a cooked grid.  My question
now is how to troubleshoot the grid.  There are two braided wires,
one on each side, emerging from the window frame and soldered onto
the grid.  Should a voltage exist between these two wires?  Should
I measure between the two wires, or between one wire and the car frame?
Any other suggestions?  Where do the wires lie that connect the grid
to the fuse box?

Thanks for your attention!
-- 
	Jeff Percival ...!uwvax!uwmacc!jwp