Rear Defogger / Radio Noise

[Rapidtransit]

I have a 2001 LS V8. When I use the rear defogger, only the upper portion seems to clear leaving the bottom still with fog. Also the radio develops a lot of static when the defogger is switched on. When I switch the defogger off the radio plays normal. I checked with a magnifing glass to try to find a break. I think I found a weak spot. When I took a piece of wire and jumped across the two weak points, it made no difference, the radio still had static.
Any ideas would be appreciated.

 

[Rapidtransit]

ttt

 

[kleetus]

Isolation module is bad, or the wire is loose going into it. It's under the top deck in the back, acessible from the top once you get the cover off...