Members,
This is a bit off topic. I am trying to help my hangar neighbor with his aircraft. He is having an odd voltage issue. The plane is a 1974 Cessna 172 Skyhawk. YES this is a certified aircraft. Please keep in mind we are not repairing, modifying or adjusting anything. We are simply trying to diagnose using a hand held voltmeter.
He has a normal bus, an avionics bus, and a Zeftronics regulator.
PROBLEM: This aircraft has three instruments in the panel that can each display bus voltage. Master on/ engine off -they are displaying 11.3, 11.8 and 12.3 volts. The avionics bus reads the lowest.
We checked the sources with a fluke voltmeter and these readings are correct. This does not seem normal to either of us.
With the engine running they display 12.3, 13.8 and 14.1 volts
QUESTION: what could be causing the difference?
I am thinking this electronic (Zeftronics) regulator, or perhaps some bad grounds?
This is a bit off topic. I am trying to help my hangar neighbor with his aircraft. He is having an odd voltage issue. The plane is a 1974 Cessna 172 Skyhawk. YES this is a certified aircraft. Please keep in mind we are not repairing, modifying or adjusting anything. We are simply trying to diagnose using a hand held voltmeter.
He has a normal bus, an avionics bus, and a Zeftronics regulator.
PROBLEM: This aircraft has three instruments in the panel that can each display bus voltage. Master on/ engine off -they are displaying 11.3, 11.8 and 12.3 volts. The avionics bus reads the lowest.
We checked the sources with a fluke voltmeter and these readings are correct. This does not seem normal to either of us.
With the engine running they display 12.3, 13.8 and 14.1 volts
QUESTION: what could be causing the difference?
I am thinking this electronic (Zeftronics) regulator, or perhaps some bad grounds?