Alternator not charging the battery

Tiny
FARMERLURLIN
  • MEMBER
  • FORD BRONCO
My wife has a 1995 ford bronco, which she adores, lately the alternator went out, I have replaced it 4 times, this last week we bought a new one and also a new battery, but are still having the same problem. The alternator will not charge the battery, barely touches the n on the normal indicator, and will not go up to the middle of the normal, what should I be looking at? Any ideas would be great.
Tuesday, September 18th, 2007 AT 3:53 PM

9 Replies

Tiny
RASMATAZ
  • MECHANIC
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Get a voltmeter-read the battery before you start it-record it, now start it up wait for a few minutes-hit the head lites and heater at high-what's the reading?
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Tuesday, September 18th, 2007 AT 6:33 PM
Tiny
RASMATAZ
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Go back to index

Inbox : Message
From: farmerlurlin
To: rasmataz
Posted: Sun Sep 23, 2007 4:20 pm
Subject: the 1995 ford bronco. Alternator not charging the battery
reading was 12.1 on battery before starting it up, after starting and head lights and heat on high getting a 11.4. Ignition problem

Its not charging/reconditioning the battery-remove the wiring connector on back of alternator and jump A to F with a small wire fire it up-now what's the reading? If it goes up the regulator is bad

Also the battery is on the low side a good battery before start up should 12.4 or + to kick that starter and engine friction.

Good Luck /Reputation points and Donation is very much appreciated to keep us going in this website otherwise we might shutdown due to lack of funding.
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Sunday, September 23rd, 2007 AT 7:24 PM
Tiny
RASMATAZ
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Follow the instructions below-this will help you.


https://www.2carpros.com/forum/automotive_pictures/12900_bronco_alty_1.jpg




https://www.2carpros.com/forum/automotive_pictures/12900_bronco_atlty_test_1.jpg

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Sunday, September 23rd, 2007 AT 10:48 PM
Tiny
FARMERLURLIN
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Thank you so much for the diagram and the information, will perform the testing this afternoon.
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Monday, September 24th, 2007 AT 11:15 AM
Tiny
FARMERLURLIN
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Thanx for the diagram it helped! I am at the point of asking if you have any idea which wire out of the alternator is for ground? Iused a jump wire from the F screw to back of alternator casing and it started charging so am thinking its the alternator ground wire.
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Monday, September 24th, 2007 AT 5:42 PM
Tiny
RASMATAZ
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It'll probably overcharge the battery-what's the voltage reading while engine running.

Do this read the ohms on terminal A and battery negative terminal should read 4-250ohms anything less than that-the field winding is either shorted or grounded-Alty problem.
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Monday, September 24th, 2007 AT 8:05 PM
Tiny
FARMERLURLIN
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Where is the ground wire on the alternator?
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Tuesday, September 25th, 2007 AT 12:18 AM
Tiny
RASMATAZ
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The alternator casing is the ground-there's 4-circuits involving with FORD's Alternators.

A-battery power

I-charge/ammeter circuit

S-stator winding

F-field winding

If you jump A to F on the harness this will bypass the regulator it has no control over the alternator therefore the alty will put out everything its got towards the battery, if this happens the regulator is bad.


https://www.2carpros.com/forum/automotive_pictures/12900_icon77_6.gif

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Tuesday, September 25th, 2007 AT 2:23 AM
Tiny
FARMERLURLIN
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After all the wonderful advice from Rasmataz, thank you so so much, wife is so happy! All it turned out to be was the ground wire off the back firewall, took it off, sanded it, hooked back up and getting great readings, indicator way up on the m for the normal. This web site is terrific, we will be definately be sending a donation. Thank you so much!
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Tuesday, September 25th, 2007 AT 10:29 PM

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