Yesterday on departure climb, I had a low voltage warning for the first time.
The voltage showed 12.5V at 2500rpm and normal climb attitude. (alarm is set at 13.0V) I looked around for anything unusual electrically, and noticed the fuel boost pump (older AFP version) was still on. I turned the fuel pump off, and the voltage returned to 13.0; warning light went out. Amp indications were absolutely normal thruout... i.e. when the fuel pump was switched on there was not a large jump in amperage, but there was a 0.5 V drop each time. (My ammeter measures current going into the battery from the alternator.)
I turned the boost pump on and off a couple of times during the flight and each time saw the same voltage drop with no perceptible change in amp draw.
Any ideas what's going on?
The voltage showed 12.5V at 2500rpm and normal climb attitude. (alarm is set at 13.0V) I looked around for anything unusual electrically, and noticed the fuel boost pump (older AFP version) was still on. I turned the fuel pump off, and the voltage returned to 13.0; warning light went out. Amp indications were absolutely normal thruout... i.e. when the fuel pump was switched on there was not a large jump in amperage, but there was a 0.5 V drop each time. (My ammeter measures current going into the battery from the alternator.)
I turned the boost pump on and off a couple of times during the flight and each time saw the same voltage drop with no perceptible change in amp draw.
Any ideas what's going on?