Re: [f-AA] Generator/Regulator Trouble Shooting Help Needed

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Sam Burke

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Dec 19, 2015, 7:32:39 PM12/19/15
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I am need of some of the LIST’s brainpower, my generator would normally show a charge on my amp-meter with the engine RPM above 1600, now nothing shows even at 2400 rpm. 

12 Volt Generator Measurements;  Field Terminal: 16 ohms, Armature Terminal: 14 ohms to ground, it changes a bit when I turn the prop. 

Voltage Regulator: Three terminals; the battery terminal is open circuit since the internal relay pulls in when the generator generates enough voltage. The armature terminal ( I assume this is the armature turning) reads 33 ohms to ground and the field terminal ( assumed to be the armature terminal since the regulator terminals are not marked) reads 1.0 ohm to ground. 

I have tried shocking the generator field by sparking the battery to the field but that did not help. 

A wiring diagram is attached if it helps. 

Any suggestions would be appreciated. 

Sam Burke 
N6404C  1947 USAF L16a (7BCM)  C85-12 
Santa Maria, California 

David Polley

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Dec 19, 2015, 8:05:29 PM12/19/15
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Flash the field from bat. Jumper from bat to f terminal 1-2 seconds.than run up. Sometimes two our three tries.

David E Polley

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Sam Burke

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Dec 19, 2015, 8:11:38 PM12/19/15
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David,

I did flash the field to the battery but only for about 1/3 second. I will try it, thanks.

The model numbers of the generator and regulator are Delco-Remy 1101890 and 118736 I think. These show up on the type certificate for other Aeronca similar aircraft with electrical systems.

Regards,
Sam

Richard Murray

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Dec 20, 2015, 2:43:24 AM12/20/15
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Sam,

Here is a really good article on this subject.


It gets informative when you get down to the education heading.

Richard in OH where the temperature is getting warmer again this week. What a difference from a couple of years ago.

Sam Burke

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Dec 20, 2015, 2:57:38 AM12/20/15
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Thanks Richard

Looks like a good writeup

danv...@gmail.com

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Dec 20, 2015, 9:05:33 AM12/20/15
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Sam
Somewhere in the system there is probably a "starter contractor" switch that closes the electrical system completely except to the starter when the starter switch is activated.  It looks like a solenoid and is often overlooked in trouble shooting. 
Often these fail slowly and interrupt various other electrical engine components and radios, etc. and when it fails completely the starter won't activate. It's location on any given aircraft varies and is likely to be anywhere it was convenient for the original installer to put it and somewhere the current owner would never think to look. 
Here's a good guide for novices:
Good luck. I hate electrical problems. 
Dan v

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Sam Burke

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Dec 20, 2015, 4:40:12 PM12/20/15
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Thanks Dan

Great writeup, I will print out a copy and keep it in my file.

Regards,
Sam
47 L16a Santa Maria California

Sam Burke

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Dec 26, 2015, 11:36:52 PM12/26/15
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Dear List,

I did a number of tests including shocking the generator field to the battery for 5 seconds and shorting the field to ground to eliminate the regulator and the test results point to the generator. Any suggestions as to what could be the problem with my generator?
My plan is to remove the sheet metal strap from the back of the generator to expose the brushes and see what the problem may be.
How hard is it to remove the generator from a C85-12?

Regards, and Happy New Year
Sam N6404C 1947 USAF L16a C85-12
Santa Maria, California

Thomas Holmes

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Dec 27, 2015, 8:12:07 PM12/27/15
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Sam,
pull the engine, remove the generator, drop it in the trash and order a light weight  alternator and components.
Tampa Tom

danv...@gmail.com

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Dec 27, 2015, 8:38:20 PM12/27/15
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Sam 
You will not get better advice then Tom's.  
Dan v


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ryanae...@gmail.com

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Dec 27, 2015, 9:20:54 PM12/27/15
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I also agree with Tom....something like a B&C alternator conversion should be on everyone's upgrade list!

Gregg Horrell

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Sam Burke

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Dec 28, 2015, 1:23:26 AM12/28/15
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Tom

I have thought about doing an upgrade to an alternator but if it is an easy fix like replacing a brush older or a brush on the generator I would prefer to save the $600 it would cost to purchase an alternator. The thing I like about an alternator is that they will charge the battery at idle rpm. Does anyone on the list have an an alternator for sale or a suggestion on where to get one that is approved for my C85-12 engine?

Regards,
Sam

P. S.

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Dec 28, 2015, 9:12:15 AM12/28/15
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Sam
   I had problems with my generator 25 years ago everything checked out but wouldn't work in airplane. It turned out to be a bad master switch everyone was bypassing to do their checks.

Phil


P. S.

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Dec 28, 2015, 9:38:02 AM12/28/15
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That was 15 years ago. Cell phone keypad!

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danv...@gmail.com

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Dec 28, 2015, 10:07:37 AM12/28/15
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Sam
As Phil suggests, are you sure the problem is the generator? or alternator? (You are using both words to describe the same appliance.)
The master switch and the other controllers that turn on and off the flow of electricity can fail in ways that present with a variety of symptoms.  

And which ever it is, I strongly suggest you get it fixed or replaced before flying again. I know of an 0-200 engine that quit over water very soon after the low voltage light came on in flight. The gears for the generator drive shaft failed inside the accessory case and the engine was seriously damaged. The pilot (who is my friend and AME) survived the ditching but the plane did not. He had no prior problems with the system before this incident flight. 
This happened almost exactly this date two years ago.  Your problems reminded me and this the caution. 


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Scott Johnson

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Dec 28, 2015, 10:55:54 AM12/28/15
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Take the gen to an auto shop and have them test it. The other option is the Zeftronics voltage regulator. It is a solid state unit and has troubleshooting light codes on the side of the case

However if cash allows, scrap and go with the alternator conversion. 

Scott

Rainbow Flying Service

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Dec 28, 2015, 11:49:13 AM12/28/15
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On a Delco Remy type generator  if you ground the field while running you should get full output if the generator is good.  What the regulator does is control the grounding of the field. 
 
 
 
 
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Sam Burke

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Dec 28, 2015, 2:00:54 PM12/28/15
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Ron (Rainbow)
I grounded the field and no output.

Rainbow Flying Service

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Dec 28, 2015, 2:05:47 PM12/28/15
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That would indicate a fault with the generator 
 
 
 
 
-------Original Message-------
 
From: Sam Burke
Date: 12/28/2015 11:00:37 AM
Subject: Re: [f-AA] Generator/Regulator Trouble Shooting Help Needed
 
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Rich Dugger

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Dec 28, 2015, 5:59:47 PM12/28/15
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Probably just brushes.
Find a shop to replace them.
Tell them it's  for your uncles antique tractor or an airboat if they adk.
You have to flash the field afterwards.

Doug Rounds

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Dec 28, 2015, 7:03:58 PM12/28/15
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All those generators are usually spin off of automitive
generators--sometimes the same with a different part number and higher
price.

Roger Anderson

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Dec 28, 2015, 7:14:22 PM12/28/15
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Took a Tri Pacer generator that had a frozen bearing (some years ago) to Antelope Valley Auto Electric, up in Lancaster Ca. , when I worked at ZLA.  . They said, "off a Chrysler, huh?" I said, "yea".   For about $20 they replaced bearings and made it live again.  It lived happily ever after.  roger

From: "Doug Rounds" <captg...@gmail.com>
To: aer...@westmont.edu
Sent: Monday, December 28, 2015 6:03:37 PM

Subject: Re: [f-AA] Generator/Regulator Trouble Shooting Help Needed

Sam Burke

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Dec 30, 2015, 1:00:52 AM12/30/15
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Many trial and error tests today with no progress. Pulling the generator soon and taking it to a local tractor supply shop (Magneto Electric of Santa Maria) for rebuild. I will bring the regulator with the generator at the same time so it can be tested. A pilot friend has a replacement generator that he will gift to me if it runs as a DC motor ( he said this is a good test).
The question is; can I remove the generator without pulling the engine? Not much room between the generator and the firewall socket.

Regards,
Sam N6404C

Rainbow Flying Service

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Dec 30, 2015, 11:38:38 AM12/30/15
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Sometimes the commutator gets glazed over and the brushes loose electrical contact. I have fixed this with some fine sandpaper glued to a stick and held on the commutator while running. 
 
 
 
 
-------Original Message-------
 
From: Sam Burke
Date: 12/29/2015 10:00:38 PM
Subject: Re: [f-AA] Generator/Regulator Trouble Shooting Help Needed
 
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Cy Galley

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Jan 4, 2016, 10:44:13 PM1/4/16
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IIRR, one has to drain the oil first. Then is can be removed.

 

From: aeronca...@westmont.edu [mailto:aeronca...@westmont.edu] On Behalf Of danv...@gmail.com
Sent: Sunday, December 27, 2015 7:38 PM
To: aer...@westmont.edu
Subject: Re: [f-AA] Generator/Regulator Trouble Shooting Help Needed

 

Sam 

Sam Burke

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Jan 10, 2016, 2:30:46 AM1/10/16
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Cy

I am currently removing the generator but I do not see the need to drain the oil since the oil level in the sump is below the level of the starter flange. Correct me if I am wrong. My engine is a C85-12.

Sam
N6404C

Cy Galley

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Jan 10, 2016, 5:39:41 PM1/10/16
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You are right/ It is the C-145. O-300

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From: aeronca...@westmont.edu [mailto:aeronca...@westmont.edu] On
Behalf Of Sam Burke
Sent: Sunday, January 10, 2016 1:30 AM
To: aer...@westmont.edu
Cc: Sam & Pat Burke; Lane Tufts
Subject: Re: [f-AA] Generator/Regulator Trouble Shooting Help Needed

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