N2897M
Well-Known Member
Hi All,
A question for the electrical experts. I just replaced the analogue loadmeter in my 1978 PA28161 with a Davtron M475VA digital volt/ammeter. While the ammeter operates correctly, the volts do not make sense.
With only battery power applied to the airplane (engine not running), the voltmeter shows 7.5 which cannot be correct (new battery, no starting/charging issues). Further, the Aspen shows a more reasonable system voltage of 11.8.
After engine start with the alternator on, the voltage displayed jumps to 15 while the Aspen once again shows a more correct value of 13.6.
I have attached a picture of the Aspen/Davtron displays, as well as a link to the Davtron wiring diagram. Before I fly the aircraft back, I was wondering if anyone can provide a clue as to why the unusual voltages.
Thanks!
www.aviaaero.com/M475VA.pdf
A question for the electrical experts. I just replaced the analogue loadmeter in my 1978 PA28161 with a Davtron M475VA digital volt/ammeter. While the ammeter operates correctly, the volts do not make sense.
With only battery power applied to the airplane (engine not running), the voltmeter shows 7.5 which cannot be correct (new battery, no starting/charging issues). Further, the Aspen shows a more reasonable system voltage of 11.8.
After engine start with the alternator on, the voltage displayed jumps to 15 while the Aspen once again shows a more correct value of 13.6.
I have attached a picture of the Aspen/Davtron displays, as well as a link to the Davtron wiring diagram. Before I fly the aircraft back, I was wondering if anyone can provide a clue as to why the unusual voltages.
Thanks!
www.aviaaero.com/M475VA.pdf
