914 external alternator on/off randomly

Steve this is an aftermarket product made by B&C and you should contact them.  It depends on the wire system the builder used.  Sounds like they used the split buss, one for each.  That makes some sense since the interenal is a generator and the external an alternator (my electrical buddies know the differences)  The type 914 has a lot of loads for normal operation and it sounds like the external is only coming on when it is seening a heavy load. (?) 

B&C have a good web page and lots of support documents, I would start there. 

https://bandc.com/reference-library/

Cheers

Thanks, I’ll take a look at their documentation and reach out.

good question on load, voltage doesn’t seem to drop below 12 volts so don’t get a voltage warning. I also leave my batteries on a trickle charge in hangar so after startup there is not much load. Need to do more testing I guess.

thanks again! 
Steve