Simplex 733-621 — battery harness that runs from the legacy 4100 battery distribution block out to the battery.
Simplex describes this part identically in two of its own service parts lists, as Harness, Legacy 4100 battery block to battery. The block is panel-side hardware, not a battery: the same list identifies 450-323 as the Battery Distribution Block and stocks a battery block diode for it. So 733-621 is the last leg of the standby power path, landing that block on the battery terminals.
- Simplex wording, verbatim: Harness, Legacy 4100 battery block to battery
- Listed as a replacement service part in 4100U list 579-330 Rev. W and 4100ES list 579-1006 Rev. A
- Protected by fuse 208-156, listed as 30 Amp, Legacy 733-621 Battery Harness
- Legacy 4100 hardware; the 4100ES battery harness carries a different 15 Amp fuse, 208-050
Two harnesses in the same list are easy to grab by mistake: 733-532 is the 11 ft (3.35 m) 2-wire 10 Ga. red/black battery block interconnection run, and 733-525 and 733-542 are legacy power/comm bay-to-bay and box-to-box harnesses.
