Originally Posted by thx0849
Take off the steering column cover and check the wiring to the shifter lever(assuming its automatic) the wires tend to chafe in the column body and ground out blowing the use because it also powers the o/d cancel switch
I agree that it is possible for the hot wire to the TCS (O/D cancel) to chafe and short to ground. However, it is protected by fuse #20. The dash illumination and exterior running lights as a group are on fuse #31.
Downstream of #31, there is a branch circuit protected by a 5A fuse (#1) that serves only the dimmable instrument cluster and dash lights. If the 20A #31 is the one that's melting, then the problem cannot be in the dash lighting and must be elsewhere in the exterior running lamps or their wiring.
Assuming that no additional loads have been added to the exterior lamp circuit, I would look for a short to ground in the wiring that goes from the SJB to the front parking/corner lights or to the tails.