I just bought a '78 Music Man Sabre II that wasn't working properly. I had a new preamp circuit board installed, but now I'm not sure that it's working like it's supposed to.

When the coil tap toggle switch is in the left position (from the perspective of the guitar player with the guitar strapped on), the 3 way pickup selector switch has no affect at all on the sound. Is this correct? It works as it should, when the toggle is switched to the right position, but not when it is toggled to the left position.

It was not working properly when I bought it, so I have no point of reference to go by.

Thanks in advance.