Voltage Regulator Location

[markejackson02]

I have a 77 201 S/N 48.  Where is the voltage regulator located?  Not on the firewall.

Battery isn't charging and voltage is low at idle.  Going to clean / check connections before I start throwing parts at it.

 

[xcrmckenna]

I have a 77' 201 s/n 277. It's up under the copilot's side. Have fun changing it out:(
I thought I was having issues with mine last week. But then I found the alternator pulley was way loose. I could spin it with my fingers. All good now.


Sent from my iPhone using Tapatalk

[markejackson02]

Ouch.  Looking forward to checking those connections, not.

 

[xcrmckenna]

Ouch.  Looking forward to checking those connections, not.
 

Yeah I was sooooooo not looking forward to it after I found it way up there. You might get lucky and check your pulley as well:) I also think there is an upgraded voltage regulator as well. If yours is bad it would probably be a good time to upgrade it. But please don't quote me on that.


Sent from my iPhone using Tapatalk

[MooneyBob]

I have 77 J S/N 355.

My was all the way up on the co-pilot side. Impossible to see. Almost impossible to remove. Impossible reinstall. How did they think we should adjust voltage on that? 

Changed location to more accessible one. I changed my alternator for Plane Power and I thought ( and bought ) that new regulator will work. Wrong. It's not certified for J. It is sitting on the shelf now. Super hard to get original one. I know some people send it to to Don Maxwell and he repairs them. 

[Guest]

It's not uncommon for a standard Prestolite alternator to have low output at idle.  If you have battery voltage at the field terminal on the alternator  and the output picks up and is steady when the RPM is increased te regulator is fine.

Loose connections, loose belts and worn brushes should be checked and repaired.

Clarence

[markejackson02]

Since the prop and therefore alternator belt were just fiddled with, that's the first thing I will check.  After that will start with the regulator.  Off to the hairport (as the kids call it.)

 

[carusoam]

Somebody with an M20E is sharing the same difficulty today...

Look here for a shared experience....

Best regards,

-a-

Edited May 8, 2017 by carusoam

[xcrmckenna]

If I could figure out how to load videos, I would show you how easy it was to spin my alternator pulley. What is weird I could only push the belt in maybe a 1/2in. It felt tight. The belt doesn't look worn either. I hope your problem is something easier than the regulator.


Sent from my iPhone using Tapatalk

[markejackson02]

18 hours ago, markejackson02 said:

Since the prop and therefore alternator belt were just fiddled with, that's the first thing I will check.  After that will start with the regulator.  Off to the hairport (as the kids call it.)

 

I went down to the plane and realized I had no real idea how tight the belt should be.  Battery is on a tender now.

Lycoming publishes a quite detailed service document describing methods to tighten the belt.  I opted to order a belt tension gauge.  It's called a Krikit gauge.  Used one on auto serpentine belts before ($12).  I opted not to pay the $150 for the burroughs official tool.  I guess this makes me a cheap b*****d Mooney owner.

 

[xcrmckenna]

2 hours ago, markejackson02 said:

I went down to the plane and realized I had no real idea how tight the belt should be.  Battery is on a tender now.

Lycoming publishes a quite detailed service document describing methods to tighten the belt.  I opted to order a belt tension gauge.  It's called a Krikit gauge.  Used one on auto serpentine belts before ($12).  I opted not to pay the $150 for the burroughs official tool.  I guess this makes me a cheap b*****d Mooney owner.

 

Let's say this was "not" tight enough....:) You could also put some belt dressing on it to see if it helps. Then it would give you an idea if the belt is your issue. The belt dressing is only a bandaid because it will rub off or dry up at some point. 

IMG_4285.MOV

[Tommy]

Watch Mike Busch's EAA webinar on how to systemically trouble shoot an electrical issue. Never assume and never let a mechanic talk you into replacing parts without 100% sure that is indeed the source of your problem. I do, however, think replacing your old VR with a new one like Zeftronics that has diagnostic LED indicators will save you lots of time because it can tell you whether the problem is down stream or up stream from the VR. It's also cheap and much more reliable than the original. 

[markejackson02]

I tightened the belt this weekend.  Put a load meter on the battery which turned out to be toast.  New battery on order.  Hopefully this will resolve it.

 

[xcrmckenna]

Sorry, I was hoping for a quick and cost free fix.


Sent from my iPhone using Tapatalk

[markejackson02]

7 hours ago, xcrmckenna said:

Sorry, I was hoping for a quick and cost free fix.


Sent from my iPhone using Tapatalk

I have never come across a quick cheap fix in aviation 

[markejackson02]

Installed a new G-35 after tightening the belt and things seem good.  The system voltage is around 13.5 going up to 14 when the battery is charging after the start and down to 13.3 when idling after flying for a while.

 

 

[carusoam]

14 V is a clear sign that the charge is happening. Compare that to what the battery shows after the flight when shut down...

Charging voltage is slightly higher than what the battery can actually maintain.

Best regards,

-a-

[Guest]

10 minutes ago, markejackson02 said:

Installed a new G-35 after tightening the belt and things seem good.  The system voltage is around 13.5 going up to 14 when the battery is charging after the start and down to 13.3 when idling after flying for a while.

 

 

Lead acid batteries are normally 2.1 volts per cell, 6 cell battery should be 12.6 volts fully charged at rest.  Normal charging voltage of 13.9-14.1 with the alternator at rated speed.  If you have an original Prestolite alternator they drop off quickly at idle speed.

Clarence