This is prompted by someone else's post about no turn signals. I had mine go out last summer, as well as the power windows in my '90 740. Turns out that the air cond compressor failed and with the air switch on the fuse blows, taking the other things with it which are according to the fuse map supposed to be on the adjacent fuse, which does not blow. Very odd, but there you have it. Maybe this will be helpful to someone somewhere, sometime. Or something.
I haven't fixed it yet, got a 134 converted compressor on speculation when I needed a trans and now need it so will install it when the weather is more appropriate.