Prestolite 8AR2202L alternator overcharging

Hi there,

I would be very greatful if you could help me on my mission to prevent my alternator from overcharging!

I have a brand new prestolite 8AR2202L alternator with a fixed regulator on the rear (9RC2060).

Unfortunately, after fitting this unit to my vehicle, i cannot prevent it from overcharging at some 15.5+ Volts!

Due to the unfortunate lack of quality on your wiring diagram available on the web-site, i cannot fully determine as to exactly where the wires lead off to from the regulator (the purple and orange wires to a 2 pin connector labeled with a 'A' and a 'B').

Any help on this matter would be very much appreciated and wholeheartedly received!

Many Thanks and Kind Regards,

Marc Osbourne

Marine Alternator

I have been told that a 12 Volt Lucas/Prestolite 70Amp A127 Marine Alternator, Internally regulated  will be suitable for use on my old Ford Wortham Blake PETROL / GASOLINE boat engine.

What cocerns me is that both ends of the unit are open and any sparks that could come from the unit could be highly dangerous in the engine compartment.

Is it safe to use this alternator?

The Alternator is new and just been removed from a Perkins Engine and replaced with a 24volt alternator. There is no part number on it as it has been painted grey. It has a fan behind the pully. 



regulator mod Brf20011a

We have a regulator model brf2011a sales #105-151. It has 3 wires coming from it. One red that goes to the + bat. , one black that goes to the iginition switch, and one white wire that is disconnected. The alternator is overchanging the battery and we need to know thw correct wire connections. Model might be 8rf2001a.
Please email me back as we are in Roatan.
Patrick LaGrandeur.

Wiring diagram

To whom it may concern,

I have recently perchased a 70 amp alternator series: AS123
Des no 66021136.
Could you please forward a wiring diagram to me for this particular alternator, the only attatchment points that are marked are B plus and W ??

Kind regards.


I have a 8rg2043 regulator where the adjustment screw spins with no effect on the alternator output voltage which is low at 12.6 volts.

1. How do I force the alternator (model 8mr2069ta) to full output to ensure that the alternator itself is OK since the field terminal is behind the regulator?

2. Is that regulator available for sale as a replacement part?



Technical Enquiry about Regulator



I have a 8LHA2070VB Alternator (AMPS140 VOLTS12) with a 8RG2112 Regulator Attached (AMPS7 VOLTS12).


1. Is this a current and voltage regulator (i.e. continously outputs 7 Amps at 12 Volts)
2. Does the alternator curve reflect the output of the alternator or the output of the regulator?
3. What current is required from the alternator to get full current and voltage from the regulator?


Ultimately I want to know how many rpm I need on the alternator to get full current and voltage from the regulator.




leece neville

Good morning i have a customer that has given me a number off a leece neville alternator that can't locate the number is brg2101a can you help?

Alternator - Catalina 27

Dear sirs,

I have a Catalina 27 with an 11HP Universal Atomic Diesel engine with this alternator in it. I cannot find a model number on the back. Everything on the back has been rubbed off over the years. I had it tested at a local auto shop and it is only putting out 11 volts. They really guessed on a cross-over number. I did find these numbers but they may not be correct because everything was really faint.

846 (?);

51 amps ( for certain);

12V ( for certain);

110-389 (?).


Can you tell from the photos which unit I have?


Edwin R. Knox III, AIA

Prestolite alternator AVI 110AMP,#35215335UK

1]How many poles does this alternator have[ie pulses per rotation]?
2]Do you have a performance curve for 50deg.C?,or how do I best interpolate from the curves you provide at 23.5deg.C
Tony Hannaford

Brush length - VLF3278

I, i am doing the maintenance on a marine alternator I would like to know what is the full lenght of a new brush on the alternator model number VLF3278 , 28 Vdc
Year 200126
Sales : 110-852
Thanks in advance
Marc Rochette
Electrotechnician Canadian Coast Guard