Generator Not Charging... flashing helps, but problem retu

[Prior owner]

Some of you know that I have been battling high oil temps and have been putting in some long hours to get that resolved. During a second test flight, I noticed that the ammeter was just sitting on Zero. Switched on the pitot heat and boost pump and tried to get a reaction out of it... but nothing. Just Zero amps. Here is what happened:

Today, after a fitful night of wondering whether I was going to have to pull the generator (dreading that one), I went to the airport with multimeter in hand. Hooked it up to the bus, turned on the master switch, and checked voltage. Started the plane and monitored the voltage on the bus while increasing the rpm... all the way to 2000. Nothing. No voltage change.

Then I removed all the wires to the regulator and cleaned everything and re-attached. Started the plane.... no change. Nothing on the ammeter and no change in voltage.

Decided to do a “full field test” on the generator- disconnected the generator wire from the regulator and attached it to the Bat terminal on the regulator. Removed the field wire and grounded it. 
 

Went into the plane and unscrewed my fuel flow meter and EGT gauge and Verified that everything was off or disconnected. Was about to start the plane when it occurred to me that I should probably disconnect the cluster gauge, so I reached under the panel and began unscrewing the canon plug...it wasn’t tight. Hmmm.... So I unscrewed it all the way and then started plane and ran the test- my voltmeter on the bus showed that voltage increased and decreased with rpm changes. I was careful to keep the voltage under 14 volts.

So, it’s not the generator. Must be the regulator...

I hooked everything back up in the plane, including the cluster gauge, but I left the voltmeter attached to the bus. 

I started the plane again. This time the ammeter showed a normal indication and an increase in rpm resulted in an increase in voltage. The plane was fixed!

But how? [Edit] I flashed the generator by running this test, that’s how...

Problem returned intermittently during the next flight- zero indication, then a mid scale charge, then wavering needle. Something isn’t right. Is this what a failing regulator will do? Haven’t dealt with many regulator issues before, and don’t have a bench test setup.

 

Edited August 4, 2020 by PilotCoyote

[RLCarter]

field needed flashed?..generators need that sometimes 

[carusoam]

Could be... the flash...any time a perfectly operating generator isn’t operating any longer...

It gets reflashed...  then all is well again...

Otherwise, the field wire is all about controlling what the generator does... if something interrupted the signal going down that line... then nothing happens....

PP thoughts only, not a mechanic...

Best regards,

-a-

[moodychief]

What voltage regulator do you have?  I installed a zeftronics regulator and periodically will have zero output from the generator.  I run the engine to 1700 rpm and cycle the master (after turning all electrics off)and the generator comes on line.  That is now on my checklist when checking the amps.  

[Prior owner]

Sorry, I had forgotten about this thread that I started.. I have a 50 Amp Delco generator and a 1119224 Delco Regulator. The Loadmeter was darting all over place, with or without a Heavy load on the system. 
 

I went through the entire charging system, removing all cables and grounds and cleaning up every terminal. ran an ohmmeter through every wire and switch. I also cleaned The points in my regulator, and it has now started behaving a lot better...  (2 second video is how it was acting all the time, but no more). Voltage  has now stabilized and The loadmeter needle is not moving so much in flight now.

Battery capacity test performed and battery is in great condition.

I’d like to get a Zeftronics, and probably will in the near future. I also have a generator switch.

 

[carusoam]

Wow, Great pic Coyote!

I didn’t know it was possible to take a color pic of the sticks and stones and springs voltage regulator....
 

My C’s got mis-adjusted... and slowly boiled a battery... 
 

The zeftronics is an easy upgrade...

and does an amazing job at holding the voltage right where it is supposed to be... Even with the 65C’s generator...

Pp thoughts only, not a mechanic...

Best regards,

-a-

[RLCarter]

7 minutes ago, carusoam said:

I didn’t know it was possible to take a color pic of the sticks and stones and springs voltage regulator....

now thats funny

[Prior owner]

1 hour ago, carusoam said:

Wow, Great pic Coyote!

I didn’t know it was possible to take a color pic of the sticks and stones and springs voltage regulator....
 

My C’s got mis-adjusted... and slowly boiled a battery... 
 

The zeftronics is an easy upgrade...

and does an amazing job at holding the voltage right where it is supposed to be... Even with the 65C’s generator...

Pp thoughts only, not a mechanic...

Best regards,

-a-

The trouble with the old Delco-Remy aircraft regulator is that they solder over the screws on the current and voltage units that you would normally use to adjust the air gap between the points ( I don’t think they wanted you to attempt to adjust these units in the field). 

To correctly adjust The regulator, first you need to know the air gap spec for each unit (good luck finding that spec for the aircraft version), and then you can adjust the points spring tension on the back. All you can really do is adjust the spring tension for the points with these, which is not really the proper way to adjust the regulator. And yes,  The spring tension adjustment on the voltage unit is very sensitive- 1/8 Turn might raise the max volts +1.2 V . Easy to cook a battery...

Yes, Zeftronics is the way to go. But Nobody has them right now. Hopefully the factory will get back to making them soon.

[carusoam]

Great details Coyote!

Somebody did post the manual for the old delco-Remy device around here somewhere...

Old fuzzy memories...

Best regards,

-a-

[Prior owner]

Yep. @47U sent the Delco manual to me. It was very helpful. It also references a few Delco service bulletins, which contain a little more info, but the points air gap spec (if it is different than the automotive version of the regulator), remains a mystery. Probably better that it remains a mystery- these old units should just be replaced when they misbehave , considering the gravity of having a charging system failure in an aircraft. 

[jamesm]

I believe still I have zeftronics voltage regulator  for  generator as well generator off a '67C. If you  are  interested

James '67C

[Prior owner]

5 hours ago, jamesm said:

I believe still I have zeftronics voltage regulator  for  generator as well generator off a '67C. If you  are  interested

James '67C

PM’d you...

[moodychief]

I was told by my local generator shop that those were used in tractors...not automobiles.  The three post on an automobile generator are equally spaced whereas ours have one post further away from the others.  Even though I installed a Zeftronics, I had the generator shop overhaul my Delco Remy just in case I need it.  We have used it several times to troubleshoot other local Vintage Mooney’s to determine they weren’t having regulator problems.

FWIW I was also told (by an unnamed MSC) the gascalator gasket is the same used in the vintage John Deere tractors.

[Prior owner]

Some Tractors Have starter-generators. Wondering why you never see them on recips, but always on turbines.

[jamesm]

7 hours ago, PilotCoyote said:

Some Tractors Have starter-generators. Wondering why you never see them on recips, but always on turbines.

Starter Generator  thank Bill Lear  for that. A legend way before his time.