alternator voltage drop - Page 2

rv8ch · #11 07-08-2022, 01:09 AM

Quote:

Originally Posted by wcalvert

My IO-360 had a similar (but smaller) leak when new, but has since (180 hours) disappeared. That leads me to believe it was a front main seal settling in...

Just a guess, but mine stopped.

Exactly the same here. I thought the leak stopped because I started using 15W50 oil, or because I started using Camguard. I almost pulled the prop - happy I didn't.

Monkey · #12 07-08-2022, 08:23 AM

Check torque on the two through bolts on the nose of the engine case. I find them loose all the time on customers planes.
Those 60 amp Plane Power alts. are known to break the stator wires where they attach to the diode assy. especially if the prop isn't balanced. I've replaced several over the years.

Paul 5r4 · #13 08-05-2022, 07:36 AM

I'm with BobbyHester on this one. I LOVE my alt from the local auto parts aviation section. Less than $100. I had one of theirs fail after a couple years and they replaced it free! The other good... no GREAT thing is that no matter where I am I can likely get one... even on a Sunday! I'm happy. I will add this. I am VFR only. If I was flying around hard IFR I would likely spend the money and time for an aviation certified alternator.

Jake14 · #14 08-07-2022, 02:18 PM

Thanks for all the tips/suggestions, very helpful. Update is, I returned the AS alternator and bought the brush kit for the PP 99-1012 (internally-regulated) alternator. Installed it and the voltage went up to about 13.8 to 13.9...didn't seem good enough. Bought a new alternator from Van's as suggested and now the voltage is at 14.0 - 14.1 (voltage measured at the EFIS, AV-30 and USB outlets all correspond)

Still not the 14.3 or so I got in the first 5 years of flying the aircraft.. checking for loose wires but haven't found anything. Maybe 14.0 is enough to keep the PC680 charged? or should I look further?

rv8ch · #15 08-07-2022, 11:15 PM

Quote:

Originally Posted by Jake14

Thanks for all the tips/suggestions, very helpful. Update is, I returned the AS alternator and bought the brush kit for the PP 99-1012 (internally-regulated) alternator. Installed it and the voltage went up to about 13.8 to 13.9...didn't seem good enough. Bought a new alternator from Van's as suggested and now the voltage is at 14.0 - 14.1 (voltage measured at the EFIS, AV-30 and USB outlets all correspond)

Still not the 14.3 or so I got in the first 5 years of flying the aircraft.. checking for loose wires but haven't found anything. Maybe 14.0 is enough to keep the PC680 charged? or should I look further?

14.0 - 14.1 is what I get with my PP alternator. I have an EarthX 680c, and this is in the range they recommend (13.8 - 14.6 volts). I guess it's a similar range for the PC680, and should be fine.

lr172 · #16 08-08-2022, 12:16 PM

Quote:

Originally Posted by Jake14

Thanks for all the tips/suggestions, very helpful. Update is, I returned the AS alternator and bought the brush kit for the PP 99-1012 (internally-regulated) alternator. Installed it and the voltage went up to about 13.8 to 13.9...didn't seem good enough. Bought a new alternator from Van's as suggested and now the voltage is at 14.0 - 14.1 (voltage measured at the EFIS, AV-30 and USB outlets all correspond)

Still not the 14.3 or so I got in the first 5 years of flying the aircraft.. checking for loose wires but haven't found anything. Maybe 14.0 is enough to keep the PC680 charged? or should I look further?

I would look for resistance on the wiring that is feeding your voltage instrument or any wiring between it and the Alt. Any resistance here will under report the actual voltage being produced by the Alt. You can test this by putting your VOM directly on the battery with the engine running. This will give an idea of the actual alternator output voltage, unless there is resistance on the B lead to battery wire. The VOM on the B lead will give true output readings, but will need jumper wires as that is pretty close to the spinning prop.

Larry

petehowell · #17 08-09-2022, 11:21 AM

I've got a 60 amp breaker in the B lead Circuit. My voltage dropped from 14.3 to 13.7 one day and never went back - we isolated the breaker and found the voltage drop across it. 16 years and 2600 hrs - I was not too upset - they are $15 at Spruce.

New breaker is on the way - worth checking if you have one in the circuit.

Update - this is pretty much what Larry just said above......

Quote:

Originally Posted by Jake14

Thanks for all the tips/suggestions, very helpful. Update is, I returned the AS alternator and bought the brush kit for the PP 99-1012 (internally-regulated) alternator. Installed it and the voltage went up to about 13.8 to 13.9...didn't seem good enough. Bought a new alternator from Van's as suggested and now the voltage is at 14.0 - 14.1 (voltage measured at the EFIS, AV-30 and USB outlets all correspond)

Still not the 14.3 or so I got in the first 5 years of flying the aircraft.. checking for loose wires but haven't found anything. Maybe 14.0 is enough to keep the PC680 charged? or should I look further?