Volvo: windows/roof 2000 S70 GLT SE turbo, fuse block, master windows

Question
Ray,
one of several problems with this (would be othervise) great car:
windows/roof/mirrors stopped not work. Located an aluminum clad relay (or fuse?) for that hidden in the fusebox (position #37) and discovered that it was extremely hot, melting some of the plastic around the contact. Checked voltage to that and when ignition is on there is ~12.4 volts, while windows or roof switches are off. I assume there should be no voltage there if the switches are off. Is that the right assumption? If yes than there is a short in one of the switches. Next i planned to check master windows switchpack that i recently cleaned under a microscope and restored connections and the roof switch. Is this the right approach? Why could be the reason the Wagner 20A relay did not turn off when it got so hot?
I have three of S70s and that my kids drive and the only way to "survive" the repairs is to do as much as possible w/o going to a dealer.
Thanks for any help with this.
Sincerely,
DM

Answer
Dmitri,
Since the fuse has voltage and is burnt I would suspect that there is a loose connection and has built up enough heat to melt the plastic. But since there is not a short in the system it did not blow the fuse. If there is power at the fuse block that seems normal, but it might not be hot after the ignition switch, witch is standard. I never try to clean the master window switches, just replace them. The buttons become loose and make poor contact, more so because it is not in proper position not corrosion. So get the power wire at the engine fuse block repaired and see how well things work, change the master switch.