Author Topic: 65 amp vs 100 amp alternator  (Read 4839 times)

Offline hooD

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65 amp vs 100 amp alternator
« on: June 23, 2016 - 10:16:25 PM »
I'm considering replacing my original factory alternator just because its old.   It has the single belt pulley.
Is there any good reason to go with the 100 amp instead of the 65 amp i have now?
-Larry
member since AUG 2007
http://www.youtube.com/watch?v=NvrWiLgDm7Y

southeastern michigan usa
             
 
            
1973 'CUDA 340
 
original owner
37,117 miles
  
:grinyes: *click my E-Body* :grinyes:




Offline Bullitt-

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Re: 65 amp vs 100 amp alternator
« Reply #1 on: June 23, 2016 - 10:23:22 PM »
Not if your going with an OE type...Problem with all of this style is low output at low RPM & the higher rated unit puts out no more than the original.

Unless it's failed I wouldn't worry about it... a new set of brushes might prevent a failure otherwise the rebuilt unit you get may not last any longer..
Wade  73 Rallye 340..'77 Millennium Falcon...13 R/T Classic   Huntsville, AL
Screwed by Photobucket!

Offline Cudaragtop

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Re: 65 amp vs 100 amp alternator
« Reply #2 on: June 23, 2016 - 11:31:30 PM »
I installed an 80A upgrade kit in mine. I have a Square Back not the "Correct" Round Back for a 70. Not trying for correctness either though...
They sell them for both styles though

Here is the thread.
http://www.cuda-challenger.com/cc/index.php?topic=102616.0

Happy with the results.


- Randy D.
1 of 88 1970 340 4-Speed 'Cuda Convertibles
69 Barracuda Fastback Project Album https://goo.gl/photos/XjsAsx4LDo7psimU8
----o00o--'(_)'--o00o----

Offline dodj

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Re: 65 amp vs 100 amp alternator
« Reply #3 on: June 23, 2016 - 11:33:29 PM »
No need to increase alt output if are not adding electrical accessories. :2cents:
Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline hooD

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Re: 65 amp vs 100 amp alternator
« Reply #4 on: June 24, 2016 - 02:18:43 AM »
No need to increase alt output if are not adding electrical accessories. :2cents:

Not adding any accessories.
-Larry
member since AUG 2007
http://www.youtube.com/watch?v=NvrWiLgDm7Y

southeastern michigan usa
             
 
            
1973 'CUDA 340
 
original owner
37,117 miles
  
:grinyes: *click my E-Body* :grinyes:

Offline hooD

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Re: 65 amp vs 100 amp alternator
« Reply #5 on: June 24, 2016 - 02:23:33 AM »
Unless it's failed I wouldn't worry about it... a new set of brushes might prevent a failure otherwise the rebuilt unit you get may not last any longer..

New brushes sounds like a good idea.  And you're right about the new/rebuilt units not lasting as long.  I seriously doubt that anything manufactured today would last 44 years.
-Larry
member since AUG 2007
http://www.youtube.com/watch?v=NvrWiLgDm7Y

southeastern michigan usa
             
 
            
1973 'CUDA 340
 
original owner
37,117 miles
  
:grinyes: *click my E-Body* :grinyes:

Offline hooD

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Re: 65 amp vs 100 amp alternator
« Reply #6 on: June 24, 2016 - 02:30:48 AM »
Here is the thread.
http://www.cuda-challenger.com/cc/index.php?topic=102616.0

Happy with the results.


Tell me more about the #8AWG wire you ran from alt output to starter. 
-Larry
member since AUG 2007
http://www.youtube.com/watch?v=NvrWiLgDm7Y

southeastern michigan usa
             
 
            
1973 'CUDA 340
 
original owner
37,117 miles
  
:grinyes: *click my E-Body* :grinyes:

Offline Bullitt-

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Re: 65 amp vs 100 amp alternator
« Reply #7 on: June 24, 2016 - 07:10:51 AM »
Larry are you having some issues your wanting to resolve?
Wade  73 Rallye 340..'77 Millennium Falcon...13 R/T Classic   Huntsville, AL
Screwed by Photobucket!

Offline Cudaragtop

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Re: 65 amp vs 100 amp alternator
« Reply #8 on: June 24, 2016 - 09:24:16 AM »
Tell me more about the #8AWG wire you ran from alt output to starter.

A #8AWG from the Alternator output to the Starter Relay
Provides a direct low loss supply of alt current to the relay without going through the firewall bulk head connector, to the Ammeter and back through the bulk head to the relay.
I did not bypass the ammeter but  path of least resistance is the #8

Good write up here.
http://www.madelectrical.com/electricaltech/amp-gauges.shtml

Another thread on the bypass wire.
http://www.cuda-challenger.com/cc/index.php?topic=104798.15
- Randy D.
1 of 88 1970 340 4-Speed 'Cuda Convertibles
69 Barracuda Fastback Project Album https://goo.gl/photos/XjsAsx4LDo7psimU8
----o00o--'(_)'--o00o----

Offline dodj

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Re: 65 amp vs 100 amp alternator
« Reply #9 on: June 24, 2016 - 09:37:33 AM »
Tell me more about the #8AWG wire you ran from alt output to starter.
Just adding that one wire without doing anything else will help your bulkhead connector live a longer life. It will shunt the majority of the current charging your battery directly from the alt to the battery without going through the bulkhead connector and the ammeter, back through the bulkhead connector and then to the battery (starter solenoid post). Your ammeter will still move a bit but not really be an accurate representation of the  state of charge/discharge anymore, but the chance of burning your bulkhead connector or ammeter is reduced.
Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline Cudaragtop

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Re: 65 amp vs 100 amp alternator
« Reply #10 on: June 24, 2016 - 09:43:11 AM »
I bought one of these off Ebay for a voltage meter. Plugs into the cigar lighter socket. I only plug it in when I'm in the car. One of these days I'll change the hot wire to a switched source.

- Randy D.
1 of 88 1970 340 4-Speed 'Cuda Convertibles
69 Barracuda Fastback Project Album https://goo.gl/photos/XjsAsx4LDo7psimU8
----o00o--'(_)'--o00o----

Offline Fern

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Re: 65 amp vs 100 amp alternator
« Reply #11 on: June 24, 2016 - 10:42:20 AM »
I bought one of these off Ebay for a voltage meter. Plugs into the cigar lighter socket. I only plug it in when I'm in the car. One of these days I'll change the hot wire to a switched source.




Not to change the subject but do those plug in volt meters work, accurate?

Offline Cudaragtop

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Re: 65 amp vs 100 amp alternator
« Reply #12 on: June 24, 2016 - 12:21:54 PM »
Not to change the subject but do those plug in volt meters work, accurate?
The one I got is accurate and since the Ammeter needle never moves now with the Alt bypass wire, I can see what is happening with the charging system without adding a gauge pod somewhere.
- Randy D.
1 of 88 1970 340 4-Speed 'Cuda Convertibles
69 Barracuda Fastback Project Album https://goo.gl/photos/XjsAsx4LDo7psimU8
----o00o--'(_)'--o00o----

Offline burdar

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Re: 65 amp vs 100 amp alternator
« Reply #13 on: June 24, 2016 - 12:48:32 PM »
That's exactly what I want to do with my Dart.  I replaced the AMP gauge in the dash with an oil pressure gauge(68 Darts never came with an oil pressure gauge)and  I put a toggle switch on the dash where the original lighter was.  However, there is a chrome plug covering a small hole in the console ash tray.  It looks like the hole is for another lighter socket.  That would work perfectly for a plug-in VOLT gauge.

Offline hooD

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Re: 65 amp vs 100 amp alternator
« Reply #14 on: June 24, 2016 - 07:00:44 PM »
Larry are you having some issues your wanting to resolve?

The only issue i have is at idle.....the gauge shows discharge until rpms are increased.   
-Larry
member since AUG 2007
http://www.youtube.com/watch?v=NvrWiLgDm7Y

southeastern michigan usa
             
 
            
1973 'CUDA 340
 
original owner
37,117 miles
  
:grinyes: *click my E-Body* :grinyes: