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Amperage reading- 912

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Posted

Ok, so my electrical skills are probably my achilles heel of wrenching on planes. Have a 912ULS in the plane, runs great, but I have no reading on my amperage gauge when its running, or ever for that matter. Needle does not move. All the connections on the rear of the gauge are made and it lights up with the panes. What readings should it be showing when running or not running with the master on?

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Posted

Can you post the electrical schematic or go in and trace it out and post? Impossible to figure out anything without knowing how it is wired. beautiful panel by the way!

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Posted

Hey Neloner,

With your master switch OFF you should see the needle on the zero mark.

when you switch your master ON you should read a discharge on your gauge (needle showing about 2 amps left of zero). As soon as you have started your engine your needle should go to the positive charge side (right side of zero) and recharge your battery + feed the electric consumers. You will have a higher reading just after starting and when your battery has fully recovered, your reading is going to show the actual electric consumption of the different consumers you have switched on.

If your alternator or regulator fails you will read a negative value (left of zero) even with engine running.

Cheers.

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Posted

...and when your battery has fully recovered, your reading is going to show the actual electric consumption of the different consumers you have switched on.

Maybe... it depends on how it is wired. Most cars for instance, will only tell you the amount of current going into or from the battery. The devices that are running will not register. I've seen airplanes with the ampere gauges wired like flywise says and I've seen them like most cars have. As Chris  stated, one really needs to have a schematic to know what it should be reading. But it definitely should be reading. :-)

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Posted

Everything on my bird goes through the amp gauge so I know how much juice everything is pulling and it also shows when charging or a flashing light if its discharging.  Its an EI gauge of ? ?  vintage.  It is heavy though and will get tossed soon and replaced with something much newer and lighter.

:BC:

 

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Posted

Hmmm, cant seem to find a schematic, I know Ive seen one somewhere. Guess ill crawl behind the panel and have a looksie. Hoping its a gauge issue and not a generator issue!

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Posted

If your battery is not going dead on you then the generator is putting out, just don't have the amp gauge wired in right.

:BC:

 

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Posted

If you have a power jack like a cigarette lighter outlet or something like that, or easy access to the power buss, put a voltmeter on and measure the voltage with the engine off and then running at a few thousand RPM. It should be 12.X volts off and somewhere between 13 and 14.5 with the engine running several thousand RPM depending on the charge state of the battery. If the voltage gets above 13 the charging system is working. Over time the voltage will rise to higher than 14, but that can take some engine run time at cruise RPM.

It's really important to know how the ammeter is wired to know if it is working (properly). Remember these engines are only capable of delivering about 15 amps or so at FULL cruise RPM and MUCH lower than that at lesser RPMs. So it is possible if you are running 10 amps of accessories you won't see any current charging the battery. However, since you don't see any current draw when you turn the master on and then turn on accessories, something doesn't sound right.

Personally I don't see much benefit from an ammeter since the alternator doesn't put out enough current to quickly overcharge the battery. If it were me I'd replace it with a volt meter. Much more informative from my perspective. 

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Posted

Ok, so I turned on the master and then one by one all of my accessories. The needle went down a tiny bit for everything I turned on, so I guess its working. Guess Ill start up the plane this week and see if I can get the needle to move up with some RPMs. I started this plane for the first time a few days ago and noticed the needle didnt move but maybe my accessories were sucking up as much as the little generator puts out at relatively low rpm. 

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Posted

Ok, so I turned on the master and then one by one all of my accessories. The needle went down a tiny bit for everything I turned on, so I guess its working. Guess Ill start up the plane this week and see if I can get the needle to move up with some RPMs. I started this plane for the first time a few days ago and noticed the needle didnt move but maybe my accessories were sucking up as much as the little generator puts out at relatively low rpm. 

Turn off all accessories before you start the engine - the ammeter should move to positive as soon as engine starts, then as soon as the battery catches up on charging it should move back to about neutral or a little above.   EDMO

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Posted

Ok, so I turned on the master and then one by one all of my accessories. The needle went down a tiny bit for everything I turned on, so I guess its working. Guess Ill start up the plane this week and see if I can get the needle to move up with some RPMs. I started this plane for the first time a few days ago and noticed the needle didnt move but maybe my accessories were sucking up as much as the little generator puts out at relatively low rpm. 

Turn off all accessories before you start the engine - the ammeter should move to positive as soon as engine starts, then as soon as the battery catches up on charging it should move back to about neutral or a little above.   EDMO

ahhhh, so it only will show charging if the battery is a bit low? It has been on a tender all along so Maybe its fully charged and not charging then

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Posted (edited)

Ok, so I turned on the master and then one by one all of my accessories. The needle went down a tiny bit for everything I turned on, so I guess its working. Guess Ill start up the plane this week and see if I can get the needle to move up with some RPMs. I started this plane for the first time a few days ago and noticed the needle didnt move but maybe my accessories were sucking up as much as the little generator puts out at relatively low rpm. 

Turn off all accessories before you start the engine - the ammeter should move to positive as soon as engine starts, then as soon as the battery catches up on charging it should move back to about neutral or a little above.   EDMO

ahhhh, so it only will show charging if the battery is a bit low? It has been on a tender all along so Maybe its fully charged and not charging then

The starter takes a heavy amperage - the battery will need a quick charge from the alternater after you start engine.   The length of charging time depends on how long you have to use the starter to start the engine.   Disconnect the tender before starting.   EDMO

Edited by EDMO

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