Battery capacity and dd autopilots

[Jim Cate]

The fact that your system voltage drops so low under load hints strongly at elderly batteries with high internal resistance. A thorough load test would be a good idea, but time and effort required is high. I'd venture that battery replacement is in your near future! Doing a check of other house loads is also needed so that you understand where the power is going, autopilot or no... knowing your energy budget is an important bit of knowledge.

Good luck with it,

Jim

[Squanderbucks]

With your noticeable power drop when turned on I would run a couple of checks after adjusting your software settings.
Check wiring for good grounds. Possibly put a clamp on meter on the power wire + to verify the actual AMPDraw.
If your batteries are good there should not be a large voltage drop when the unit is operating. Especially initially.
Check the grounds.