G1000 amp discharge

[Kitch]

G1000 206. Intermittent amp discharge on main batt. Recycle alternator and discharge goes away. Both volt meters maintain 28v constantly. New alternator all connection’s checked and rechecked. Any feedback appreciated.

 

[Klaus M]

Tighten the alternator belt.

Once the belt begins to slip it will lose it's friction and stop charging.

 

[Kitch]

It’s fiddle string tight. Gremlins… I hate em lol

 

[Bell206]

Intermittent amp discharge on main batt. Recycle alternator and discharge goes away. Both volt meters maintain 28v constantly.

Couple questions:
1) Is the ammeter on the 1000 or is this the OEM meter? How many amps are indicted when discharging?
2) As to "both voltmeters" one in the 1000 and the OEM voltmeter? And no movement on either when notice the amp needle move?

 

[Rockymountain]

If your volts stay 28, it is not your alternator. Could be an indicator issue, a big amp draw somewhere, although can’t think of anything outside of a short that could pull that many amps in a Cessna. Or some issue with how the devices pull off the battery versus the alternator. The answer may lie in the electrical schematic so you can see where the electrons flow.

 

[Klaus M]

There's a bunch of Cessna Service Bulletins covering the late model aircraft charging issues. Don't know which ones apply to you or you've done already but find this one:
Cessna SEB-24-01

 

[Kitch]

Couple questions:
1) Is the ammeter on the 1000 or is this the OEM meter? How many amps are indicted when discharging?
2) As to "both voltmeters" one in the 1000 and the OEM voltmeter? And no movement on either when notice the amp needle move?

Both the Main battery and standby battery have their own V and A meter on the 1000

When I landed last night it showed an 85 amp discharge when I shut the alt off the discharge started to decrease back towards zero.

If your volts stay 28, it is not your alternator. Could be an indicator issue, a big amp draw somewhere, although can’t think of anything outside of a short that could pull that many amps in a Cessna. Or some issue with how the devices pull off the battery versus the alternator. The answer may lie in the electrical schematic so you can see where the electrons flow.

To me it almost acts like a bad ground somewhere. A&P suspects the part that does the job of a voltage regulator (I can't remember exact nomenclature)

There's a bunch of Cessna Service Bulletins covering the late model aircraft charging issues. Don't know which ones apply to you or you've done already but find this one:
Cessna SEB-24-01

I will check into that !


Thanks everyone for the insight !!

 

[Bell206]

When I landed last night it showed an 85 amp discharge when I shut the alt off the discharge started to decrease back towards zero.

My bad. I missed the 28v reference. I take it this is a restart 206? Since the main voltage didn't flicker or the low volt light didn't illuminate, I'd pop the cover on the Master Box and take a look at the current sensor for the main battery. That's what drives the ammeter. And given I can't think of anything that would pull 85 amps (outside an internal battery issue) without popping a circuit breaker then return to normal you may have an issue with the sensor or its connections. What is the main battery voltage reading when you shutdown the engine?

I'll look to see if I can find a reference diagram for the master box to show the current sensor.

 

[Kitch]

My bad. I missed the 28v reference. I take it this is a restart 206? Since the main voltage didn't flicker or the low volt light didn't illuminate, I'd pop the cover on the Master Box and take a look at the current sensor for the main battery. That's what drives the ammeter. And given I can't think of anything that would pull 85 amps (outside an internal battery issue) without popping a circuit breaker then return to normal you may have an issue with the sensor or its connections. What is the main battery voltage reading when you shutdown the engine?

I'll look to see if I can find a reference diagram for the master box to show the current sensor.

Good question I can't answer.... I'm sure I looked at it after shutdown, but It didnt sink in what it was reading. I was wondering about and internal problem with the battery too. They are going to test the battery in the meantime.

The extra frustrating part is we are supposed to launch on vacation Thursday bright and early and I really don't want to fly cattle class.... 1st world problems I know LOL

 

[Bell206]

They are going to test the battery in the meantime.

If they are performing a OEM capacity check it should find any internal battery issues.

If you look in the 206 service manual 24-60-00 Fig 201, Sh. 3 & 4, it will show where the ammeter current sensor is located depending on S/N or SB upgrade. The sensor is just another form of an ammeter shunt. I believe for the 1000 aircraft they are a Garmin part. Have your mechanic check the sensor connections and I believe there is also a resistance check for the sensor, but just don't recall where it is. Being a resistor they can get weak over time with heat. Good luck.

 

[Klaus M]

While working on a T206H today it reminded me of a time when the ignition key ring had several keys on it and intermittently engaging the starter in flight. The characteristics where similar to your problem. Very high amperage draw but didn't change the voltage.

The pilot didn't figure it out until one of the times after taxiing back to parking and shutting down but the propeller kept going around.

Make sure you don't have an ignition switch that is worn out or you have more then two keys on your ignition key ring.

 

[douglas393]

I think someone may have said this as well, but not sure if this is the case, but my experience with the G1000 (10 years with my T182T and now 2 years with my T206H) is that when I got erratic readings that made no sense and were not supported by secondary behavior of other sensors that should have been affected it was invariably a bad sensor or sensor wire. Erratic amperage discharge with rock stable voltage seems to suggest this. Not sure if you can swap the wire but this may be a cheap diagnostic.

 

[Kitch]

While working on a T206H today it reminded me of a time when the ignition key ring had several keys on it and intermittently engaging the starter in flight. The characteristics where similar to your problem. Very high amperage draw but didn't change the voltage.

The pilot didn't figure it out until one of the times after taxiing back to parking and shutting down but the propeller kept going around.

Make sure you don't have an ignition switch that is worn out or you have more then two keys on your ignition key ring.

Ignition switch is fairly new. Nothing extra hanging on the key.... When I was 16 and showing off my F250 I just built my grandfather said "What's all that **** hanging on the your keys ? You know boy that's gonna wear out your ignition and cause problems" From that day forward its been the key only for me LOL

I think someone may have said this as well, but not sure if this is the case, but my experience with the G1000 (10 years with my T182T and now 2 years with my T206H) is that when I got erratic readings that made no sense and were not supported by secondary behavior of other sensors that should have been affected it was invariably a bad sensor or sensor wire. Erratic amperage discharge with rock stable voltage seems to suggest this. Not sure if you can swap the wire but this may be a cheap diagnostic.

Its erratic enough that I tend to think its nothing more than the panel is getting bad information from somewhere, but I paranoid enough to chase it until I find the problem or it goes away or gets sold for a newer 206