My girlfriend's car, a 91 e36 (316 auto) has a problem with the electric windows. They haven't worked intermittently for a week or two and now they don't work at all. The fuse is ok and there is a supply to it.

I've also checked for a supply on the safety cut out switch and actual window switches, but theres no power on either.

I wondered if it could be a faulty relay, but I don't know where the relay is situated in the fusebox.

Any suggestions?