PCCs, of which the 1003 is really one despite its hand controller, won't run reliably if the line voltage is less than 380. Boeing-Vertol Lighter than Rail Vehicles require a minimum of 480 volts. The Muni had to upgrade its DC distribution system when it got the PCCs (during rush hour the voltage got as low as 150 or less at the Zoo, but the Iron Monsters didn't care) -- had to do it a again for the LRVs.

PCCs trucks aren't designed to be used on open track like the SN main line. It breaks the equalizer bars on B-2 trucks, but I forget what happens with to the B-3s. PCCs are designed to be started, run a block or two, and stopped at the next passenger stop. Running them for prolonged periods at speed, for miles, can cause problems with the resistor ribbons if the operators aren't careful.