Author Topic: Alternator not charging! Help  (Read 1967 times)

Offline cudaAD20

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Alternator not charging! Help
« on: May 24, 2015 - 09:48:07 AM »
Hi guys,

The alternator is not charging an only gives a total voltage output of 12v, even when the electric be cool fans go on, the output from the alternator is the same and does not increase..

Help please!

All the wires were changed and upgraded to better grades.. Any other things I should look for?

The alternator is a TUFFSTUFF 100 amp




Offline BS CUDA

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Re: Alternator not charging! Help
« Reply #1 on: May 24, 2015 - 10:06:39 AM »
Voltage regulator? I keep a spare one in the glove box.

Offline 4Cruizn

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Re: Alternator not charging! Help
« Reply #2 on: May 24, 2015 - 10:08:33 AM »
Electrical is not my strong suit . . . Where do you live at?   What I do have is a small little shop close to me that specializes in alternators . . . Would test for free.   :2thumbs:

Offline cudaAD20

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Re: Alternator not charging! Help
« Reply #3 on: May 24, 2015 - 10:29:12 AM »
Voltage regulator? I keep a spare one in the glove box.

It's a new regulator  :clueless:

Offline ShelbyDogg

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Re: Alternator not charging! Help
« Reply #4 on: May 24, 2015 - 11:03:16 AM »
It's a new regulator  :clueless:

And you think it's good?
At Carlisle, I showed the guys that I had 3 spares in my car. Never needed them but use them for testing. Only other part is your alternator and wiring.
Test the alternator at a parts store? They can also test the VR.  Make sure that you have it grounded well at the firewall.
Rob

3 E-bodies, Megasquirt-1v3.0, Edelbrock Pro-Flo-1, Holley C950, FAST EZ-EFI; say no to carbs...yes to throttle bodies

My Pace Car restoration thread:
http://www.cuda-challenger.com/cc/index.php?topic=44869.0


Offline 734406pk

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Re: Alternator not charging! Help
« Reply #5 on: May 24, 2015 - 06:42:33 PM »
May I suggest an old school test? Use a test light and confirm you have power to the output terminal of the alternator (engine not running and key off). If you have power, turn the key on but don't start the engine. Now take a hacksaw blade or screw driver and touch the alternator pulley with it. If the tool your using sticks to the pulley from magnetism from the field, your alternator is ng and the reg is working. The hacksaw blade works best. The magnetism is pretty strong it will be obvious, good luck!
1973 Challenger 440 6 pack auto 3.91 rear
2012 Dodge Ram 3500 dually 6.7 Cummins Fleece EFI Live
1973 Challenger 318 2bbl auto 2.73 rear 22.5 mpg RIP
1970 Challenger TA 340 4bbl auto-Sold and sad
1999 Dodge Ram 3500 dually 5.9 Cummins Fleece tuned VGT-sold
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Offline Chryco Psycho

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Re: Alternator not charging! Help
« Reply #6 on: May 24, 2015 - 08:55:05 PM »
You need 12v from the blue wire to the voltage reg on the firewall & the blue field terminal on the Alt , the green wire from the alt goes back to the reg & grounds through the regulator , so make sure the reg is well grounded , if you still have no charge either the reg or alt is bad

Challenger - You`ll wish You Hadn`t

Offline cudaAD20

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Re: Alternator not charging! Help
« Reply #7 on: May 25, 2015 - 02:40:07 AM »
You need 12v from the blue wire to the voltage reg on the firewall & the blue field terminal on the Alt , the green wire from the alt goes back to the reg & grounds through the regulator , so make sure the reg is well grounded , if you still have no charge either the reg or alt is bad

I have double checked what you mentioned above and everything seems intact.

When disconnecting the BE COOL electric fans, the voltage increases and everything seems to be normal.. Therefore do you think I just need a higher amp alternator? The one I'm using now is the TUFFSTUFF 100 amp, is there anything higher? Or do you guys agree that I just need a higher amp alternator?

Offline Chryco Psycho

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Re: Alternator not charging! Help
« Reply #8 on: May 25, 2015 - 10:24:15 PM »
electric fans draw a lot of amperage so yes the alt may not be able to keep up

Challenger - You`ll wish You Hadn`t