Fuel Pump Lo Resistor Location

[B2C2]

I suspect the resistor that is in series with the lo position for the rear fuel pump switch in my 1969 T337D may be bad as the fuel pump runs on the Hi setting but not on Lo and the switch tests good. Can someone tell me where this is located? I looked at the parts catalog and service manual but can't find the location. I figured I would ask the group before poking around.