I will check the banacing valve. Since I installed the new master cylinder and bleed the brakes I can’t get the luminated brake light to go off unles I remove the wire from the valve.
The indicator light, if it the switch is working correctly, is a warning that either the front or rear hydraulics is not developing pressure. In other words, there's a leak, air, or similar problem on either the front or the rear. 1970 Chrysler Imperial Hydraulic Brake Service Guide Safety Switch
It is located before the proportioning valve. This remains true even with the later combination tee, switch and proportioning valve. The only difference is that its all internal. Your '73 would have come with a combo valve.
Since you haven't mentioned extra movement, then its probably air or not getting fluid and pressure from either the front or rear of the M/C.
This is '73 also explains the switch and valves. 1973 Chrysler Brake Reconditioning Guide Safety Switch Cutaway
Proportioning valve needs nothing special. Not sure if your 73 has a metering valve. But if it does, it is better to open it while bleeding. If your bleeding the traditional way with a helper, one wheel at a time, the metering valve is pressure opened anyway. 1970 Bleeding advice
