Alternator Not Charging

Tiny
EVILPUPPETMASTER
  • 2003 FORD RANGER

Electrical problem 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

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

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Tiny
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I would have the battery tested just to make sure it was good. Here is guide to help you do that.

https://www.2carpros.com/articles/car-battery-load-test

here is a guide and wiring diagram (below) so you can do some testing.

https://www.2carpros.com/articles/how-to-check-a-car-alternator

and

https://www.2carpros.com/articles/how-to-check-wiring

Please let us know what happens so it will help others.

Cheers, Ken

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Monday, October 25th, 2010 AT 10:19 AM
Tiny
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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
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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
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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
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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
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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
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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
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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
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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
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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
Tiny
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I have 4.0 engine
I'll order new alt, replace it and let you knowN
thanks for your help
Alex

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Sunday, October 31st, 2010 AT 8:50 AM
Tiny
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I thought you already replaced the alternator?Why don't you pop that alternator off and take it to the auto part's store and have it tested you can't drive it anyways.

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Sunday, October 31st, 2010 AT 4:04 PM
Tiny
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I did replaced it. There is no shop in the city that has bench test for ford alternator working.
Just in case I bought another one today(also brand new) installed it and.
It does not charge again. Same thing.
Charging light comes on and it s reading 11.76 volts on the battery. So now I know that it s not alternator.
This is real mystery.
What next.

Common saturntech9, we got to get to the bottom of this.
Thanks for your help
Alex

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Sunday, October 31st, 2010 AT 5:20 PM
Tiny
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Any ideas where fusable links are on this vehicle
Thanks

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Sunday, October 31st, 2010 AT 5:39 PM
Tiny
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You checked the fuse link's to the alternator already. The black and orange to the B+ terminal you said had battery voltage. Also the yellow and white wire is the other fuse link to the alternator and you said it had battery voltage. If you look at the wire diagram I sent you it show's a white and black jumper wire that run's from the two S terminal's from the pic of the alternator you posted look's like that wire all by itself is that jumper wire that goes to the voltage regulator peel the tape back and see it that wire lead's to the white and black wire to the voltage regulator connector. Remove the battery cable first then use the low ohm's setting to see if the black and white wire is connected to the wire off by itself with all the wire's discounted. Let me know what you find.

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Sunday, October 31st, 2010 AT 6:06 PM
Tiny
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Ok, black and white wire is connected to the wire off by itself. There is a continuity between those two.
This is driving me crazy.
Any other ideas. I am currently charging my battery.

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Monday, November 1st, 2010 AT 8:56 AM
Tiny
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Another quick update,
I disconnected black/orange (b+) wire
and connected volt meter directly to the alt output.
While idling it produces, about 15-20 volts

If I increase RPM s it gives me up to 45 volts.
When I connect black/orange wire back it gives me same
output that I have on the battery (12 volts)

yellow/white wire gives me about 2 volts less the the battery so about 10 Volts while truck is running.
When it s not running it gives me same reading as on B+ Terminal (12 volts)
Thanks again

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Monday, November 1st, 2010 AT 10:38 AM
Tiny
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This is crazy you have everything your supposed to according to the diagram. You have the two power feed's and the jumper wire the only one let is the charge light wire which has nothing to do with it charging. So with all the wire's hooked up and the engine running what does the B+ read for voltage?

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Monday, November 1st, 2010 AT 11:20 AM
Tiny
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HI again,
B+ reads exactly as batterys Positive terminal. The voltage depends of charged state of my battery. When it's fully charged it reads 12.65 v. When I let the track idle for 5-10 minutes drops below 12.
Charging red warrning light is on.
I do not know what to do.
Anything else you can think of

Thanks
Alex

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Monday, November 1st, 2010 AT 12:06 PM
Tiny
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Hi,
i got some good news. I just cleaned small wire connector going from negative battery terminal to the frame and now started partially charging.
The red light goes on and off and I could see lights getting bright and then dim again so I will continue and clean other connections to the frame and engine.
Would you know where main frame connection is located?

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Monday, November 1st, 2010 AT 2:06 PM

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