2003 FORD RANGER ALTERNATOR NOT CHARGING

  • Tiny
  • evilpuppetmaster
  • 2003 Ford Ranger

Electrical problem
2003 Ford Ranger 6 cyl Four Wheel Drive Manual 152000 miles

Hi,
I have a problem with my alternator not charging battery at all.
I have already replaced it with the new alternator and same issue happens.

The red Alt light comes on (with different intensity)
sometimes it's really visible RED and sometimes it's very dim.

The car starts and runs fine.
I tried to remove positive wire from the battery while the car is running and it stops running instantly.

I have checked all fuses and they are good.
Battery seams fine since I can Charge it with my external charger.
Any Ideas?

Thanks
Alex

Monday, October 25th, 2010 AT 9:56 AM

22 Answers

  • Tiny
  • saturntech9
  • Expert
  • 28,864 posts

I would have the battery tested just to make sure it was good. Did you have the new alternator tested before you put it in?Also do you have a multimeter to do some testing?

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Monday, October 25th, 2010 AT 10:19 AM
  • Tiny
  • evilpuppetmaster
  • Member

Thanks for your response. I will test the battery today. I have not tested the alternator but will bring (old one) it to be tested today aswell.(Old and new alt have the same simptoms)

Yes, I do have Multimeter and I can test anything you suggest.

Alex

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Monday, October 25th, 2010 AT 10:29 AM
  • Tiny
  • saturntech9
  • Expert
  • 28,864 posts

Let's start with you testing the battery and the old alternator let me know what you find and we will go from there.

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Monday, October 25th, 2010 AT 10:49 AM
  • Tiny
  • evilpuppetmaster
  • Member

Well, after visiting 5 local parts stores none of them had completely working bench alternator tester.

I did test the battery and it turns out it's in perfect working order.

Is there any other way I can test this alternator in the vehicle using multimeter?
Please let me know
Thanks
Alex

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Friday, October 29th, 2010 AT 8:54 AM
  • Tiny
  • saturntech9
  • Expert
  • 28,864 posts

Charge your battery all the way up start it up let it idle take your multimeter and check at the battery post's with it idling and see what the voltage reading is. Let me know what voltage you get.

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Friday, October 29th, 2010 AT 1:17 PM
  • Tiny
  • evilpuppetmaster
  • Member

Hi,
Definitely not charging.
Battery is fully charged, truck is idling and I am reading 11, 99 volts on the battery.
I have also measured voltage on the big positive wire on the alt and I get the same reading.

Checked all fuses and they are good
Any other ideas
Thanks
Alex

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Saturday, October 30th, 2010 AT 10:12 AM
  • Tiny
  • saturntech9
  • Expert
  • 28,864 posts

Alright here's what you need to check next the black and orange wire to the B+ terminal on the alternator should have battery voltage to it. Also check the yellow and white wire terminal A at the alternator should have battery voltage also. Let me know what you find.

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Saturday, October 30th, 2010 AT 11:32 AM
  • Tiny
  • evilpuppetmaster
  • Member

Yes, you are correct. When vehicle is not running it reads 12.26 v on both wires

Alex

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Saturday, October 30th, 2010 AT 11:53 AM
  • Tiny
  • saturntech9
  • Expert
  • 28,864 posts

On the alternator with the battery disconnected the two S terminal's there is a white and black wire running to those two terminal's see if those two terminals are connected from post to post.

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Saturday, October 30th, 2010 AT 12:50 PM
  • Tiny
  • evilpuppetmaster
  • Member

Ok, i disconnected positive wire from the battery,
There are 3 wires on the voltage regulator,
yellow/red, white/black and green
there is another white wire going to another terminal.
Please see picture:
which wires do you want me to test
do you want me to test those terminals with or without cables connected
thanks for your help.
Alex


http://www.2carpros.com/forum/automotive_pictures/586217_alt_1.jpg

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Saturday, October 30th, 2010 AT 3:55 PM

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