My alternator on/off has suddenly become intermittent and I'm not sure of how the wiring circuit looks and whether the panel mounted On/Off switch is controlling a relay or switch in the alternator, or is just a switch in the alternator power line?
I started the engine on Friday and the voltmeter immediately jumped to positive charge, BEFORE I'd turned the alternator on. I toggled the switch on and off and the positive charge remained, so I assumed the switch had become u/s, particularly on the 2nd flight that day when the same thing happened.
Yesterday morning I took the panel switch out and measured resistance across the terminals, which was about 1400 ohms, which increased to infinity when I switched off the alt field switch. I disconnected one of the leads and tested the switch itself, which correctly read 0 and infinity resistance when cycled on and off. I reconnected the lead, remounted the switch and restarted the engine, no charge initially and then charging when I switched the alt on.
Later, I started the engine to fly and the alternator went straight onto charging again before I'd switched on the alt....... I switched off the alt field and the charging voltage went down a little, but still showed a charge......!!??
Does anybody recognise these symptoms?
I started the engine on Friday and the voltmeter immediately jumped to positive charge, BEFORE I'd turned the alternator on. I toggled the switch on and off and the positive charge remained, so I assumed the switch had become u/s, particularly on the 2nd flight that day when the same thing happened.
Yesterday morning I took the panel switch out and measured resistance across the terminals, which was about 1400 ohms, which increased to infinity when I switched off the alt field switch. I disconnected one of the leads and tested the switch itself, which correctly read 0 and infinity resistance when cycled on and off. I reconnected the lead, remounted the switch and restarted the engine, no charge initially and then charging when I switched the alt on.
Later, I started the engine to fly and the alternator went straight onto charging again before I'd switched on the alt....... I switched off the alt field and the charging voltage went down a little, but still showed a charge......!!??
Does anybody recognise these symptoms?
