Autohelm ST50 Wind Instrument

[LngTmSlr]

I've set up an STng circuit to tie together an e7 MFD, P70/ACU100/eV1/ST4000+ Autohelm, and AIS650. Using an ST to STng converter, I've connected an i40 Bidata speed and depth instrument and an old Autohelm ST50 Wind instrument. I've updated software and done initial startup of the e7 MFD and Autohelm system. Everything seems to be running well except the i40 and ST50 wind instrument won't turn on (blank screens). I have verified the ST to STng converter is supplying 12V to the ST50 at the right hand ST connector (when looking at the back of the instrument). The i40 Bidata Speed/Depth instrument is connected to the left hand ST connector on the back of the ST50 instrument. Voltage coming out of the ST50 at the left hand ST connector is 4.27 VDC, probably not enough to engergize the i40 unit.

Questions:
1. Is the ST50 capable of supporting the i40 Bidata unit? If so, am I looking at a failed ST50 Head (The unit was working well before I installed the new equipment)
2. If there is no obvious fix for the ST50 setup, I would consider looking for a used ST60 Wind Instrument display unit or a new i60 Wind display unit (which would tie in with STng leaving the i40 Bidata alone on the ST to STng converter) because it appears they would work with my existing masthead unit. Can you confirm that these two instrument heads should work with the masthead unit installed with the ST50?