My abs warning light is on, it has been into my local garage but is showing code 177 on their "gadget". and is specified as being a fuse problem. "fuse supply power" or something like that

All the fuses in the box under the bonnet are ok, wondered if there was a hidden set of fuses somewhere.
I don't have a manual
its 320i 1995
Can anyone help please

Geta Haynes manual,the best manual you can buy for$20 at your auto store or at http://haynes.com it may be the computer,generally located uder dash board on passenger side.