[VetteVet]

It's quite possible that the brake wire inside the steering column has chafed the insulation off in a spot that grounds when you turn the wheel and when you apply the brakes it blows the fuse.
If it was shorted down stream from the firewall, it could be one of the turn signal wires.
Yellow or dark green, but that would open up the possibility that just operating the turn signals or using the emergency flashers would also blow the fuse.

I would disconnect the half moon connector and do a continuity check on the white wire to the column housing while turning the steering wheel. If you get a reading then you have found the short.