I am trying to track down a weird issue I have with my alternate trim system. I wired up two switches so that I can run my pitch trim from my IBBS backup battery in the event the main electrical system or the wiring for the main trim system (buttons on control sticks and VP-X Pro) fails. I have a Norm/Alt switch that selects whether the alternate trim or VP-X outputs are connected to the trim servo. The alternate trim up/down momentary switch is wired from an output of the IBBS and a firewall ground.
The VP-X can control the trim servo just fine in Norm mode.
The IBBS can control the trim servo just fine in Alt mode, but only when the main battery contactor (and thus the VP-X) is off. There is not a voltage difference between the trim motor outputs when the master switch is on and the alternate trim switch is run up or down. There is a ~12.5V difference when the master is off and I run the alternate trim switch. (Positive voltage one direction, negative the other, as expected.)
I am not using pass-through power on the IBBS, just the charging input and the four power outputs. The IBBS is charged by one circuit output of the VP-X. The VP-X also has the aux battery voltage input correctly wired to the battery information wire on the IBBS.
I am trying to rule things out. And before I really go nuts ruling out every wire in the panel, I want to rule out these questions:
Does the IBBS turn off its outputs when the charging input is active?
Is there any other set of conditions in which the IBBS turns off its outputs?
I hope someone knows. My sanity is awaiting your replies. Thanks in advance!
The VP-X can control the trim servo just fine in Norm mode.
The IBBS can control the trim servo just fine in Alt mode, but only when the main battery contactor (and thus the VP-X) is off. There is not a voltage difference between the trim motor outputs when the master switch is on and the alternate trim switch is run up or down. There is a ~12.5V difference when the master is off and I run the alternate trim switch. (Positive voltage one direction, negative the other, as expected.)
I am not using pass-through power on the IBBS, just the charging input and the four power outputs. The IBBS is charged by one circuit output of the VP-X. The VP-X also has the aux battery voltage input correctly wired to the battery information wire on the IBBS.
I am trying to rule things out. And before I really go nuts ruling out every wire in the panel, I want to rule out these questions:
Does the IBBS turn off its outputs when the charging input is active?
Is there any other set of conditions in which the IBBS turns off its outputs?
I hope someone knows. My sanity is awaiting your replies. Thanks in advance!