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Topic: Alternator replacing (Read 908 times) previous topic - next topic

Alternator replacing

I'm replacing my original alternator with the exact same Leece Neville. Doesn't it need to be adjusted on output? 1996, 8.3 Cummins

Re: Alternator replacing

Reply #1 –
Keep the old one for a spare and carry it with you.

Re: Alternator replacing

Reply #2 –
If you have a diode based OEM style isolator they consume about 0.7 volts through the diodes. The OEM LN alternators had output voltage increased to compensate for the loss to keep voltage at the batteries about 13.8v.  Those adjustments and final output depend a bit on battery type and your situation.

Re: Alternator replacing

Reply #3 –
I'm keeping the old one as a spare, since these are not stocked. I assume I could run the genny to get home if you lose the alternator

Re: Alternator replacing

Reply #4 –
Quote from: dans96u295ft –
I assume I could run the genny to get home if you lose the alternator

Yes, just turn on boost and continue on. In fact I just had someone burn up an alternator and had to drive in from N. Dakota like that. I plan on doing a show & tell when when I have time to get it rebuilt as several have ask.

Mike

Re: Alternator replacing

Reply #5 –
If someone wants a functioning, adjustable voltage 160 amp LN alternator that was in my 2001 U320 let me know.  I kept it as a spare but I would rather see it in use than sitting on a shelf.

Update
It is off to a new home, better there than on my shelf.

Thanks

Re: Alternator replacing

Reply #6 –
Quote from: dans96u295ft –
I'm replacing my original alternator with the exact same Leece Neville. Doesn't it need to be adjusted on output? 1996, 8.3 Cummins

Yes.*  Does not?  It do.  Your solid state battery isolator has a 0.7V voltage drop across the diode.

Art

*Unless you have a voltage sense wire.

Re: Alternator replacing

Reply #7 –
Quote from: Roger & Susan in Home2 –
If someone wants a functioning, adjustable voltage 160 amp LN alternator that was in my 2001 U320 let me know.  I kept it as a spare but I would rather see it in use than sitting on a shelf.
I'll take it if it's free and you have a commercial shipping account. It's a heavy devil. I got rid of our dash AC and am going install a second alternator where the compressor was. No more isolator and will replace the existing boost solenoid with a latching model.. C/H 24200 Amazon.com: Cole Hersee 24200 Latching Solenoid: Automotive

Pierce

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Re: Alternator replacing

Reply #8 –
Quote from: Old Toolmaker –
Yes.*  Does not?  It do.  Your solid state battery isolator has a 0.7V voltage drop across the diode.

Art

*Unless you have a voltage sense wire.

IF this truly is a DUVAC alternator, there is a SENSE WIRE/TERMINAL that is on the chassis battery side of the battery isolator. This automatically compensates for the voltage loss in the diode-based battery isolator.

So, alternator is told by the sense wire/terminal to put out enough voltage such that subtracting the loss across the diode-based isolator results in exactly the correct voltage to the battery.  May some small adjustment need to be made to conform with a particular brand/technology of battery-- certainly.  But the loss across the diode-based isolator is already taken into account.

Re: Alternator replacing

Reply #9 –
Yes, it is a DUVAC

Re: Alternator replacing

Reply #10 –
The aternator can be easily coverted to DUVAC. See this page for modifications: Technical Services

Pierce

Re: Alternator replacing

Reply #11 –
What is DUVAC?  What good is it?
 This is my LN and it has the same tag.

Pat,

Re: Alternator replacing

Reply #13 –
Quote from: pthurman48 –
What is DUVAC?  What good is it?
 This is my LN and it has the same tag.

Pat,

The important thing about a DUVAC alternator is that it has an external SENSE wire that senses voltage on the on the chassis battery side of the diode-based isolator.  This is important, as correct voltage "downstream" of the isolator is what matters.
 

Re: Alternator replacing

Reply #14 –
Pat,

With pic. yours is set  as a DUVAC looks like it could be OEM even.

Mike