92' 300e rear defroster inop
 

Last winter I remember the electric rear defroster not working as well as normal but forgot about it until this season. It does not work at all now. I have a large relay inthe relay cluster that clicks (also clicks with the turn signals and flasher). Does anyone know what might be the cause or what to troubleshoot? I expect there another relay, I would think so since the contacts in the big relay seem too small for that kind of current.

Also what is the recommended service book to buy for this car?

Many thanks.
R2