paulsteger
I'm New Here
I have a 6a that I bought used 3 yrs ago and recently found out if I turn off the master switch with the engine running, the main bus still has power and all electrical stuff stays on. Not sure how long it?s been like this because my usual shutdown sequence of electrical, mixture, master, mags doesn?t detect this. Here is what I know. It appears to be wired like Van?s sample wiring diagram, except it has no separate voltage regulator, so regulator must be integral to the alternator as car alternators have been for many years. Looking at the schematic it looks like when you shut off the master, the master relay opens up which causes the + side of the battery to disconnect from the master bus. Meanwhile the alt side of the spit master switch disconnects the alternator field from the bus. Without 12 volts to supply the alternator field, the alternator output should drop out, so it also no longer supplies the bus, so bus should go to 0 volts. Mine doesn?t. My master relay does drop out as it should. I can hear it clunk at a low idle. The alt side of my master switch does open up and drop +12 to the alt field. If I start the engine with the field wire disconnected, then the master does shut off the bus, but the battery is discharging with the engine running. So it appears to me that once the field is excited as in a normal start situation, the alt keeps supplying output as long as the engine is running, even if the field input loses its 12 volt input.the alt does charge the battery and supply the electrical needs as it should.
I removed the alternator to have it tested by a car parts jobber. It has no identifying data plate. What company made it? Car place couldn?t test it because he didn?t have a field connector to fit it. It has 3 male spade lugs in a U shape inside a round cavity. Is it from Vans? Lycoming? A paper barcode sticker on it gave no google hits either. I?m grounded till I get this fixed
I removed the alternator to have it tested by a car parts jobber. It has no identifying data plate. What company made it? Car place couldn?t test it because he didn?t have a field connector to fit it. It has 3 male spade lugs in a U shape inside a round cavity. Is it from Vans? Lycoming? A paper barcode sticker on it gave no google hits either. I?m grounded till I get this fixed