<VV> Help!!! Fuse Problems

[Mike & Jackie]

I am finishing up a restoration on our 69 Conv. and I am having fits with 
one of the fuses.  On the fuse box it says on one side of the fuse, (gauges) 
and on the other it says (bu).  It is a 10 amp fuse.  It keeps on blowing 
out when I shift into  reverse.  The fuse box is new, the wiring harness is 
new, the bu switch is new.  After blowing three fuses, I unplugged the two 
wires from the 4 speed bu switch and have no problems blowing fuses.  Next I 
took the 4 speed bu switch out and cleaned the surface where it screws in 
the trans.  Cleaned the copper gasket and put the switch back in. I switched 
the two wires on the bu switch. Started the car and put it in reverse and 
again the fuse blew up. Do you guys have any answers for this problem?