TomTom wrote:
Could an alternator defect cause an overvoltage spike or the defect is necessarily in the regulator?
It could, but much less likely than the regulator, though Peter also raises a valid point above.
shielding of the ignition leads are connected to the ground of the whole plane, aren’t they? What about lead defect that would cause arcing in the lead?
Shouldn’t happen: a very low resistance to the ground and a low resistance of the alternator itself would shunt out the interference current from the ignition.
Ok thank you
So let’s start first with the regulator….
One issue I had with my TB20 which originally looked like an electrical issue was traced to a small leak in the undercarriage hydraulics. That then meant after a while the pressure was low enough in the cruise to start the hydraulic pump up to re pressure the system in the gear up position. It was a very brief low voltage indication that caught my attention and I didn’t get an over voltage issue at that time but I wonder if the electrical instability during that time could also manifest as over voltage.
Thank you.
We have not noticed any blinking from the gear pump indicator light….
