US / North America

Battery drain with engine shutdown

I had my 200Amp Leece Neville Duvac alternator rebuilt after it failed. After installation it charges just fine but I found that the alternator is warm even after the engine has been shut down for an extend time. In fact it run my batteries down before I realized what was happening.
I took it to a service center and they indicated that the Duvac wire was hot even with the key switch turned off. What could be causing this? Is there a relay or some switching circuit that could cause this?

Cross Reference

One of my customers needs a 24V alternator. He has a Volvo part number---9021429786.
What Leece-Neville alternator do I need for him?

Marine 90 amp alternator upgrade for 1998 Indmar 5.7L Moomba Boomerang

I want to upgrade the original 51 amp Prestolite marine alternator (part no. 8MR2084K, sales no. 110-494, Indmar part no. 775024) in a 1998 Moomba Boomerang, Indmar 5.7L gas engine, to a 90 amp Prestolite alternator. It looks like 3 different models may work: 8MR2069TA, 110-602; 8MR2033TS, 110-252; and 8MR2030TC, 110-570. Which do you recommend? Thanks, Bill

Balmar/Prestolite MC-614-AGM regulator

I have a Leece Neville 110-555, 160 amp alternator and a Balmar/Prestolite MC-614-AGM regulator. A 3.5 hp air cooled diesel drives the alternator at about 4500 rpm for charging batteries at camp. While I do not have the real manual the options are similar to the standard Balmar 614. The engine is easily overloaded at full field on the alternator. I’ve set the belt load manager to 7, its lowest setting. The unit seems to works correctly except for the engine being overloaded when I put a big load on the batteries. I then shorted the alternator temp sensor, which reduces the field to 50%. I can still overload the engine. The engine starts to smoke at around 50 amps/750 watts and falls flat on its face at 75 amps/1000 watts. Those #s don’t include other associated losses in the system so I could add around 30% to them. Is there any way to further reduce alternator output? I’m about to put a variac on the field wire and vary it that way. Any help would be appreciated and a link to the real manual would be great.

Thanks, Geno

10 hours later.

I think answered my own question. I put the variac on the field wire and could easily keep the engine from overloading with 1500 watts load on the inverter. The battery voltage dropped steadily but picked right up when I took the load off and the batteries began charging properly. It looks like 3 ohms is the magic #. I found a 10 ohm, 100 watt variable resistor on ebay and I'll put that in and and set it at the sweet spot. What this means to me, which is very important, it that I can use this small engine to run large loads for short times. I can put a table saw, compressor or small well pump on the inverter and do so with a fuel efficient engine running at a tolerable 2400 rpm.

It would still be nice to know if there's a way to do this without the resistor so don't hesitate to chime in with any ideas.

Thanks, Geno

Alternator needs 12V to start


I have 8MR2070TA connected to a Sterling Products AB12130 Alternator to Battery charger. There is no output from the alternator in this configuration. The alternator works properly when connected directly to the battery. Does the alternator need 12V on its output before it will start?


Alternator not charging full amps


My alternator is not charging up to 60 amps. Starts at 60, but will not stay and drops to 30 or lower in a short time. I have looked at the photos on the website and the adjustment switch is not in the location shown. When using the battery charger it will charge it's full amperage, but when running the engine, the alternator will not charge at 60 amps. We are on a boat and are not able to receive and on hand advice or repair,if you could get back to us at soon as possible, it will be much appreciated.

Thank you

Steve Moen

alternator output & specs

Looking at the alternator on my 1993 Catalina 34 sailboat, I read 'Prestolite Electric Co. 8RC2008A 146A 12V 51 Amps.'
Is this a fixed voltage output, and if so do you know what this voltage is? Also if it is fixed, can a modification be made to make it an adjustable output to be able to get about 14.4 volts? How do I find the specs for this alternator.


Is 8RG2604 really a 4 AMP Alternator?

I was doing some engine maintenance and decided I needed to jot down the make and model of my Alternator on my 1981 Westerbeke 58. It's an 8RG3604 and it said 4 AMPs on it. Is that right? It really only outputs 4 AMPs or am I misunderstanding something?

Here's an almost clear photo:

Thanks in advance for helping out a newbie!

Alternator Poles

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Why would I Go To A Higher AMP. Alternator

How Do I Know If I Need A Higher AMP Alt.