NEED VOLTAGE REGULATOR

[philipneeper]

Does anyone have a OCEO 20082 Voltage regulator?

[takair]

Sent you an email.

[OR75]

Zeftronics R1530B is a drop in replacement for the OECO with the same steel cannon plug. PMA part.

Not too expensive for an aviation part.

[NotarPilot]

I have an old one I took out of my J I could part with.

[philipneeper]

Does it for sure work?

[N601RX]

Depending on what alternator you have, Plane Power may have a legal replacement. If so it is about $100 cheaper than the zeftronics. It has a very stable output, mine never moves off 14.1

[philipneeper]

I'm getting my alternator tested Monday at a local shop. I keep getting a voltage light in flight. Sometimes it resets sometimes it doesn't.

[Bob - S50]

I'm getting my alternator tested Monday at a local shop. I keep getting a voltage light in flight. Sometimes it resets sometimes it doesn't.

It may or may not be the alternator.  We occasionally get the flashing volts light too but in our case we are convinced it is the annunciator.  When the light flashes our JPI shows 13.9 volts.  Just haven't taken the time to adjust the annunciator yet.

 

Bob

[philipneeper]

It's more likely not but since the plane is down for annual, might as well take the time. I'm 90% sure it's not the alternator but a regulator. When my voltage light comes on I have 0 charge so I know it's not a faulty indicator

[OR75]

not the alternator. the alternation would be working or kaput. not intermittent.

my bet would be on the alternator belt tension, or a connection or the VR

[Bob - S50]

Same here, exactly, in my '78 J. We have never been able to track down my very, very occasional voltage enunciator light, but my Aerospace Logic digital volt/amp meter is rock steady.

There is actually a procedure in the maintenance manual for adjusting it.  It goes something like: take the top off the annunciator box, using a voltmeter, set an engine RPM to produce 12.6 volts, adjust the trim pot until the light goes out, then adjust it up until the light just comes on (or vice versa).  Can't remember exactly.

 

Bob

[MooneyCFII]

I'm getting my alternator tested Monday at a local shop. I keep getting a voltage light in flight. Sometimes it resets sometimes it doesn't.

OK, you may or may not have the problem that you think you have. Here is some trouble-shooting logic for you.

 

First, you know you have a low-voltage light. This will light up for four reasons:

1. There is indeed low voltage on the bus;
2. the wiring between bus and low voltage sensor is faulty;
3. the low-voltage sensor itself is faulty;
4. the low-voltage sensor need to be adjusted.

The best way to determine if you actually have an alternator or alternator control (voltage regulator) failure is to have a separate voltmeter on the bus. If the alternator/generator system is working the bus voltage will be above 13.2V and less than 14.6V. If it is in the 11V-12.5V range the alternator/generator is off-line and you are using battery power.

 

If you don't have a voltmeter then the battery charge/discharge ammeter will help you figure out what's wrong. During normal alternator/generator operation the charge/discharge ammeter will be very close to zero since all it is showing is the trickle-charge going into a fully-charged battery (usual 1A-2A). If you think the alternator is off-line, turn on the landing light or pitot heat. That should cause the charge/discharge ammeter to show a clear discharge if the alternator/generator isn't working. If the ammeter stays near zero, your alternator is working and the low-voltage light is at fault. 

 

If you don't have a separate voltmeter for your bus, I recommend getting one. It is the most useful gauge for determining charging system health. 

[philipneeper]

OK, you may or may not have the problem that you think you have. Here is some trouble-shooting logic for you.

 

First, you know you have a low-voltage light. This will light up for four reasons:

1. There is indeed low voltage on the bus;
2. the wiring between bus and low voltage sensor is faulty;
3. the low-voltage sensor itself is faulty;
4. the low-voltage sensor need to be adjusted.

The best way to determine if you actually have an alternator or alternator control (voltage regulator) failure is to have a separate voltmeter on the bus. If the alternator/generator system is working the bus voltage will be above 13.2V and less than 14.6V. If it is in the 11V-12.5V range the alternator/generator is off-line and you are using battery power.

 

If you don't have a voltmeter then the battery charge/discharge ammeter will help you figure out what's wrong. During normal alternator/generator operation the charge/discharge ammeter will be very close to zero since all it is showing is the trickle-charge going into a fully-charged battery (usual 1A-2A). If you think the alternator is off-line, turn on the landing light or pitot heat. That should cause the charge/discharge ammeter to show a clear discharge if the alternator/generator isn't working. If the ammeter stays near zero, your alternator is working and the low-voltage light is at fault. 

 

If you don't have a separate voltmeter for your bus, I recommend getting one. It is the most useful gauge for determining charging system health. 

I been isolating it down. Fingers are pointing to a regulator.

[philipneeper]

The last thing to check is the wire to the low voltage. When my voltage light comes on my volt meter shows 0 as if all power has been lost. However all radios still operate.

[MooneyCFII]

I been isolating it down. Fingers are pointing to a regulator.

If the bus is at a steady 13.2V with other stuff turned on, and the Aspen is showing random voltage between +3V and +12V, that is *NOT* a problem with the alternator controller (voltage regulator). If it were the alternator controller the bus voltage would be fluctuating right along with the Aspen's reported bus voltage. It isn't so the alternator controller is NOT the problem with your Aspen. I suspect that your A&P is not an electrical wizard and is guessing without actually reasoning out the symptoms.

 

Now it may be that there is a problem with the alternator controller too. The fact that your bus voltage is 13.2V in flight is too low to properly charge the battery. It should be 13.8V-14.4V depending on temperature. (It should be higher when the battery is cold and lower when the battery is warm but that is also another issue.)

 

To be honest, what all this is telling me is that you need to spend some time giving your electrical system some TLC. There are a lot of connections in there and most of them haven't been touched since the plane was built. If your plane is anything like mine, over the years ham-handed people will have made "modifications" that compromised the proper protection and routing of all the wiring. Go through and inspect all the connections. Loosen, clean, and retighten the connections. Unplug and clean all the connectors before plugging them back together. Inspect all the wiring bundles to be sure they aren't chafing on anything and that the insulation is clean, intact, and un-abraded. Do this for your avionics as well. Pull the radios out of their trays. Clean the connectors. Put the radios back in. Disconnect the indicators and clean those connectors. Get your A&P to look over your shoulder if you aren't comfortable with this. You will be surprised at how much more reliable your electrical system will be if you do some PM on it.