There is an error in the BD4 Instruction Sheet, 2004 version.
As a result of this error, BD4 shows no status light and no detection lights. The solution is to connect pin 10 of the DS1 on the BD4 to a system ground such as the AX1 terminal of the DS64, Ground on the booster terminal, etc.
This connection was not shown on the original instruction sheet for the BD4.