Alternator slowly not charging - Ranger-Forums - The Ultimate Ford Ranger Resource

General Technical & Electrical General technical and electrical discussion for the Ford Ranger that does not fit in any other sub-forum.

LinkBack Thread Tools Search this Thread
Old 07-25-2010
Thread Starter
Join Date: Jul 2010
Location: sacramento, ca
Posts: 1
Alternator slowly not charging

Hello folks-

Any help on this would sure be appreciated. I have a 1996 4 cyl Ranger. Issue is, I was driving to work and the ammeter indicator started wiggling around. It started dropping, and when I revved the engine, it would pop back up- but eventually, even that wouldn’t work and it died. I was stuck without my tools, so I got a ride to the local Walmart and dropped a new battery in. Made it home, but the same thing happened as I pulled into my driveway.

Charged the battery, got out the voltmeter, battery is at 12.4 V when not running, started the engine and started at 14V, then slowly over 3 minutes with lights, AC and radio on, dropped down to 11V. Turned off engine. Took alternator out and had it bench tested at NAPA. They said it was fine. As a test, went to a Ford salvage yard and picked another one up that was also tested fine, put that one in. Same exact issue.

Checked all my fuses, the box in the engine and the panel in the cab, everything checks out fine. Seems that the alternator charges fine, until it starts to heat up. At the top of the morning, I can drive for about 20 minutes before the voltage drops.

Any thoughts? Thanks in advance for the help!

Reply With Quote
Old 07-25-2010
cheese_man's Avatar
iTrader: (1)
Join Date: Nov 2009
Location: arthur
Posts: 2,100
check the charging wiring that runs down the driver side inner fender well

look to see if the metal fender has ground through the wiring harness and is grounding out the charging system

you will have to look carefully at the wires

when you find it ,, dis-connect the battery and then repair the insulation

your best bet is to use a large piece of rubber hose insert the harness inside it then zip tie hose to the inner fender well
Reply With Quote
Old 07-25-2010
ccosgrove71's Avatar
Join Date: Jun 2010
Location: richmond,va
Posts: 185
sounds like you have a bad diode inside the alternator, the only thing you can really do is replace it.
Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
Indicator lights dead / alternator not charging battery. bakergh General Technical & Electrical 2 10-15-2016 07:50 PM
Battery not charging-new alternator 9nNancy General Technical & Electrical 6 07-14-2015 09:41 AM
Truck not charging, new alternator. Halp =[ edge2k General Technical & Electrical 1 11-08-2012 07:47 PM
Ranger not charging and chime not working jfoster2505 General Technical & Electrical 3 02-14-2012 08:23 PM
alternator not charging gary new General Technical & Electrical 9 12-21-2010 04:53 PM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -6. The time now is 02:48 PM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.