Amperage Gauge-what does it measure?
I have heard that this gauge measures the amperage load of the generator and I have heard it is the draw from the electrical system/battery. I have been told those are two different things and if I was ever to replace the ammeter in my Stinson, I would need to know which this is. I don’t understand the difference exactly so could someone please explain it to me?
Karl A Vogelheim
The stock gage measures generator current. When you turn on the master switch, the ammeter (load meter) indicates zero. Even if you turn on the landing lights. When the engine is running above 1400-1500rpm or when generator kicks in, the gage starts to indicate current. At 2000rpm there will be a nominal indication of approx 10. As electrical equipment is switched on the indication will increase. At 2000rpm the rated output of our generators is 25amps. As the load approaches this value the voltage will start to drop below 14.2vdc (normal system voltage @ 2000rpm).
On earlier automobiles the ammeter showed current going into and out of the battery. When the ignition switch was turned on the indicator (normally centered) would indicate slightly negative until the engine was started and brought above idle.
Thank you for your explanation. Does this require a special gauge if I ever have to replace it? I was thinking about getting a modern Electronics International VA-1A so I would have both volts and amps. I would think this would work perfectly fine but I figured I better check.
Karl A Vogelheim
Third attempt to reply! It should work. You will need to determine which shunt pkg you require. A bit pricy just to monitor volts. The amps are already displayed. If you have a cigarette lighter you can plug a voltmeter into that. Or you could wire in one in an empty hole. Jegs offers antique style voltmeter with red green or blue lights.
The wire from the generator runs to the Amp meter and after passing through the Guage it goes into the electrical system. That's how the Guage reads the charging current and changing that system requires a good deal of electrical work. Voltage can be read anywhere power is present so it requires no passage through a Guage. Most aftermarket engine monitors and guages will offer a voltage reading. Best thing to do is remove the entire charging system and run a alternator with a voltmeter.A lot of people don't realize this but continental actually owns a stc for franklin alt conversion,plus the numerous field approvals for the denso style mini one.I actually hold both in my planes paperwork but run the new mini style.
Thank you for the more specific information regarding the gauge.
Can you provide more information on the Continental STC? Even giving the STC number may allow someone to look it up to purchase it. Does Continental manufacture any of the parts or just the paperwork?
Karl A Vogelheim
I'm not aware of continental selling any alts but they might. They went on a buying spree scooping up everything they could get there hands on awhile ago. I probably have a few low hours ones in a box somewhere if I look and I can upload that stc if it helps anyone.I also have a revised field approval for the denso without the vacuum pad which I know was creating issues for some.
Plenty of O-470’s came with an alternator. Find an installation (like a Cessna 182) that uses an alternator and use that for approval.