THB, is your high mount working as well? Looking at my schematic from GM service information, the white wire comes from the BAS relay and hits a splice pack(or joint connector), that is part of the rear LH fuse block under the seat cushion. From this joint connector, the three powers for the lights exit. The only possible way that both rear bulbs don't brake, but the high mount does, is if there is a fault with that joint connector, C410 for left light AND C411 right both pins b, or the individual right and left sockets. The left and high mount share ground G402, and the right uses G401. If nothing works, then yes, it could be the BCM.
Wednesday, June 24th, 2009 AT 10:13 PM