Arthur -I assume by F15 you mean the 30A link fuse in a separate fuse holder next to the drivers side upper strut mount? I checked this fuse and it's ok - no hairline cracks and with ign switch on I get 12 vdc on both sides of fuse.

I also pulled the female side of the connector behind the brake vac booster on the firewall off and with ccu in defrost position and ign switch on measured voltages on this connector. On heavy gauge red wire it measured 0 - no dc volts - and on the lighter gauge yellow signal wire - same thing - 0 - no signal voltage. Does this give a clue to you about what might be problem? What is the source for the 12 vdc that is supposed to be present on the red lead? Is it through a relay or fuse ? Could OVP relay have anything to do with this? Other than no blower - ething else on my 95 e320 wagon is fine