🚀 go-pugleaf

> The rear-window defroster in my '81 Malibu has stopped working.
> I checked all the fuses in the fuse box, and none appear to be
> defective (there was a mysterious large metal-enclosed one that
> defied visual inspection).  The dashboard indicator light still
> works when I activate the defroster.  The connections at the
> rear window appear to be intact.  Can anyone suggest further
> troubleshooting?  I'd sure appreciate it.

I had an 81 Malibu wagon with the same failure. That metal box is
a relay not a fuse. The defogger draws too much current to use an
ordinary switch, also the relay has a timer built in to attempt to 
keep the defogger from melting  itself. In mine the relay went bad
(~$30). Have you checked to see if power is getting to the defogger
with a voltmeter or light? If it's not, it would be my guess that it's
the relay. If it is, then I'd suspect the window grid itself is open. 

A WORD TO THE WISE: NEVER leave a GM defogger on any longer than
necessary. They have a really nasty habit of cooking themselves if
just turned on and left for the timer to shut them off.