60 Amp Alternator Voltage Regulator Question

[ECPilot]

Hello all. I need some education/advice:

I have a 1952 Cessna 170B with a Del-Air O-360-A1A. The alternator is the Aerotech Ford 60-amp, DOFF10300J.
The voltage regulator is a mystery, it has the words, "Borg Warner" on the case but I don't know the model.

When flying, The voltage displayed on a new/good voltmeter shows an average of 13.5 volts...and the voltage goes down to 13.2V if I turn on every single thing that uses electricity.

1000RPM's = 13.2V
1800RPM's = 13.4V
2400RPM's = 13.5V

Does anyone know what model of voltage regulator works with the Ford Aerotech 60 amp alternator?

Does this seem like an alternator problem? Or, a voltage regulator problem?

Or, is it something else? Like a bad ammeter gauge? Or something?

Would replacing the voltage regulator be a good place to start? Perhaps the LAMAR VOLTAGE REGULATOR 14V DGR6-1?

If the alternator needs replaced, has anyone used the "Plane Power" alternators?

Thank you in advance. Any advice is appreciated.

[Bruce Fenstermacher]

Slow down.

You are on the right track. Confirm what you have. Compare it against what you should have.

When you say you turn on everything, what exactly is everything and how much amperage does everything add up to?

The voltages you listed are not actually bad voltages. What is the state of your battery, old, some time on it but in good shape, brand new? What is the state of this batteries charge when you took those readings? Nearly dead, half charged, fully charged? How many amps of load did you have on when you took those voltages?

Are you actually having a problem, like your battery won't charge or doesn't have enough power to start your plane? Or is there another problem?

[ECPilot]

Thanks,
I don't seem to be having any battery problems. The batter is new (2 months old) and was fully charged before, during, and after each of the last three flights.
(New voltmeter installed 3 flights ago)

...as for total amperage, that will take some work to add up, but it isn't much:
LED taxi and landing lights
strobes
nav/position lights
instrument backlighting
clock
pitot-heat
two radios
transponder
and a couple electrically powered instruments.

I was thinking the voltage would stay closer to 14.0 even with a normal load - which is why I decided to look at the voltage regulator.

With no lighting or pitot-heat...just the radios, transponder, and instruments it averages 13.5V at normal cruise RPM (2400).

[GAHorn]

Sounds like the system is working just fine.

[ECPilot]

Thanks.
And, after a bit more digging, the voltage regulator that normally would have gone with my alternator would be “C611001-0101” or equivalent. The LAMAR VOLTAGE REGULATOR 14V DGR6-1 is a direct replacement…if the one I have ever needs replaced.

[ghostflyer]

i would be very carefull about fitting a Lamar voltage regulator . Our shop had a number of them go faulty from new . Plane power regulators are ok.
To be blunt ,I wouldn’t fit a Lamar product to my lawn mower. Even brand new cessna 172 ,s are fitted with Lamar regulators go wrong . I think it’s quality control.

[GAHorn]

Zeftronics is a company in Longview, Texas which produces excellent product and great customer-support. If I wanted any regulator (generator OR alternator) other than OEM… that is where I would obtain it.

https://zeftronics.com/

Here is a copy of their Alternator Troubleshooting Guide: SEE PAGE 4 FOR “BUS VOLTAGE DROPS WITH LOAD INCREASE” and “VOLTAGE STAYS AT 13.4 TO 13.8” if you wish to troubleshoot the problem described in this thread.

Alternator Troubleshooting.pdf

Alternator Troubleshooting

(638.5 KiB) Downloaded 29 times

[David Sbur]

FWIW my old C611001-0101 vibrating points regulator for my Ford 60amp alternator slowly went south, when I put a voltage meter on the buss it was quite the spread. It finally fried my Odyssey battery so in went a Zeftronics. The buss voltage was rock steady at 14.2

I tried to keep the points clean and I did like the ability to adjust the voltage on the old regulator, but the electronic Zeftronics is so much nicer.

[n2582d]

Thanks.
And, after a bit more digging, the voltage regulator that normally would have gone with my alternator would be “C611001-0101” or equivalent. The LAMAR VOLTAGE REGULATOR 14V DGR6-1 is a direct replacement…if the one I have ever needs replaced.

First, I agree that your regulator seems to be working fine.

According to the FAA’s PMA database the other regulator which is approved as a direct replacement for Delco-Remy’s C611001-0101 is Hartzell’s R1224. If the C611001-0101 regulator is what is specified on your Del-Air STC then replacing it with a Lamar or Hartzell (Plane Power) regulator would only require a logbook entry. I agree with George in that if I was to ever replace your Borg Warner regulator I would opt for a Zeftronics unit even though it would require a field approval as it is not PMA’ed as a direct replacement. Use STC SA8031SW as supporting data on a field approval. Both the R15V00 rev. A and the R15100 rev. A would work. I have the R15V00 rev. A which includes built in overvoltage protection.

Thinking further on this, did you find, “C611001-0101 or equivalent” in the Del-Air STC paperwork? I wonder if “or equivalent” is broad enough to include a Zeftronics regulator as a direct replacement, i.e. no field approval necessary. Be worth asking your FSDO.

[ECPilot]

Thank you all. This thread is exactly why I'm happy to be in this forum.

[Bruce Fenstermacher]

In order to charge a battery the charge voltage must be higher than battery voltage period. 14.2 volts is a common target for a 12v system but lower or higher can work just as good. Said another way a system operating satisfactory at less that 14.2 does not make it a bad system that needs attention.

I wouldn't touch it but likely if you knew what you were doing and removed the cover of your regulator, you might find spring tension adjustments for the points. Like most things old regulators tend to have adjustment features for people who knew how to adjust them, newer regulators don't have adjustments cause it's cheaper to produce and no one knows how to adjust them anyway anymore. If you would adjust the correct spring tension, 14.2v could be achieved but your system won't charge any better than it is, at least a noticable difference anyway.

BTW about the only big load I see in your list is the heated pitot. Unlike in the past LEDs have made a big difference in the load. You didn't say whether your nav lights are LED or not. Incandescent nav lights could pull nearly 10 amps between the 3 bulbs. LEDs would be 1/10th of that. Your system is really just cruising along leisurely. I wouldn't be surprised if you could through 25 A load on it that you wouldn't also see your voltage rise just a bit. As is I'll bet you barely see your amp gauge move off 0.

[ECPilot]

Yeah, my tail light is LED, but the wingtips and strobes are the old type. The only major load is the pitot heat, and when I check it prior to takeoff the amp gauge flicks to show a minor load. Normally, when cruising the ammeter is basically zero (which I think is normal).

Everything seems to work. My old voltmeter was showing low/incorrect voltage so we replaced it and verified the new gauge is accurate. Now that I have accurate voltage I noticed the lower than expected voltages and that brought me to the Cessna-170-old-guys-who-know-stuff.

I'll keep an eye on it for a few more years and if it gets weird I'll go with Zeftronics or the PlanePower replacements.