I had some issues with generator and cutout where the generator may have run without being connected to and hence moderated by the battery.
I checked the generator - it ran fine and smooth when 6 volts was applied.
The I tested the diode cutout with my digital multimeter. It have a beeper function marked also with a diode symbol as if it can be used to test diodes.
Now - my problem is that it beeps both ways - with the current goes both ways.
But when I assemble it all - no current goes through the generator and when I start the engine it charges ok = i.e. the diode works as it should.
What am I missing here?
Have you actually measured the reverse current through the diode when installed in the car?
The meter is testing the diode at a very low current; about 1mA is typical.
The diode could be slightly leaky so it fails the test on the DMM but doesn't show up on the car's ammeter.
No. I have a main cut in the car that is always shut off even when parked, so a small leak does not do much harm. As long as it charges the 6 amps I measured I'm happy for now. I'm just wondering why I saw that measurement on the DMM.
Long term plan is a renovated generator with a Fun project voltage regulator.
And a small dashboard with Fun project Ampmeter and voltmeter :-)