two failed alternators - 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.

Reply
 
LinkBack Thread Tools Search this Thread
  #1  
Old 01-07-2015
Member
Thread Starter
 
Join Date: Jan 2015
Location: Lebanon
Posts: 2
two failed alternators

Details on Truck:
1992 Ranger, 4-cylinder, 2-wheel drive, 250,000 miles, oil leak likely

I got in my truck on Christmas eve after work and it wouldn't start on it's own. Had to get it jumped. co-worker said to check out the alternator, so I took it out and had it tested at an auto parts store. It failed the test and I purchased a refurbished replacement. Truck ran fine for a week.
New Year's eve, I picked up my kid from daycare and I had to get a jump again. When I was idling the engine, RPM's showed 4,500 and when I revved the engine, it would go down to 1500, like it was reversed somehow. ??? Got the truck on the road and drove about a mile and the engine died going 45 mph (after I flashed my brights at someone who pulled out in front of me). At this point, the headlights and hazards did not work, but the dome light was working somehow.
Tow truck driver said the alternator probably failed again, so I took it out and had it tested again.... failed.

I tried to fire it up last night with the replacement, replacement alternator and it wouldn't start without a jump. Once I jumped it, it ran a little rough and when I flashed the brights, the engine died.

I'm running out of ideas at this point. The battery shows 12.5 volts at rest and when the engine was running, it showed 13.5 volts. I suppose I could have really bad luck and this is the third bad alternator, but I doubt it. The guy at autozone said that the oil leak could be causing the alternator to fail, but I think he's full of it. What else could I check?
Reply With Quote
  #2  
Old 01-07-2015
Dewey's Avatar
@THE_ALMIGHTY_E4_RANGER
iTrader: (6)
 
Join Date: Feb 2013
Location: Arcadia, Fl
Posts: 2,054
Have you had the battery tested? Are all your connections at the battery clean and free of corrosion? Its possible to get a dud alternator. Before getting the new one, get it tested in the store before leaving.
Reply With Quote
  #3  
Old 01-07-2015
Fordzilla80's Avatar
YZ
iTrader: (1)
 
Join Date: Dec 2010
Location: Florida
Posts: 1,041
Quote:
Originally Posted by Dewey View Post
Have you had the battery tested? Are all your connections at the battery clean and free of corrosion? Its possible to get a dud alternator. Before getting the new one, get it tested in the store before leaving.
This. I used to work at Advance, and in the time I worked there, I probably had 3 failed alternators right off of the shelf, and numerous others where parts would actually fall out of the alternator.
Reply With Quote
  #4  
Old 01-07-2015
Member
Thread Starter
 
Join Date: Jan 2015
Location: Lebanon
Posts: 2
Yeah, but two in a row and just for me? Is there anything in my truck that could be making it fail right off the bat? The autozone tech said that my battery or starter could cause the alternator to fail. I doubt his claims..... any insight into that?
Reply With Quote
  #5  
Old 01-07-2015
RF Veteran
iTrader: (1)
 
Join Date: Jan 2014
Location: Vancouver, BC
Posts: 7,606
Could be bad alternators but you FOR SURE have a bad connection either on the Battery Ground or the "+" wires, that is the only explanation for the engine dieing when extra power is needed, i.e. the high beams.
Disconnect the ground cable then follow the "+" cable and check it's connection, usually on the starter relay, loosen and clean, this is also where alternator power connects to system, if there is a problem here you will lose ALL power in the vehicle, because battery and alternator are the only power sources.

Battery cables can "look" OK, but they will corrode under the insulation, have some tape handy, use a razor knife to cut insulation back and off about 2" from the battery end of the cable, if you see whitish discoloration replace cable, if it looks OK then tape it.

Last edited by RonD; 01-07-2015 at 10:53 AM.
Reply With Quote
  #6  
Old 01-07-2015
Dewey's Avatar
@THE_ALMIGHTY_E4_RANGER
iTrader: (6)
 
Join Date: Feb 2013
Location: Arcadia, Fl
Posts: 2,054
Quote:
Originally Posted by michaewlewis View Post
Yeah, but two in a row and just for me? Is there anything in my truck that could be making it fail right off the bat? The autozone DIMWIT said that my battery or starter could cause the alternator to fail. I doubt his claims..... any insight into that?
Fixed it for you.
Reply With Quote
  #7  
Old 01-07-2015
RLong31's Avatar
The Ban Hammer
iTrader: (5)
 
Join Date: Jul 2009
Location: Monrovia, IN
Posts: 2,629
Quote:
Originally Posted by Dewey View Post
Fixed it for you.
I don't listen to the guys that work at the parts stores.
Reply With Quote
  #8  
Old 01-07-2015
Dewey's Avatar
@THE_ALMIGHTY_E4_RANGER
iTrader: (6)
 
Join Date: Feb 2013
Location: Arcadia, Fl
Posts: 2,054
I currently work for AutoZone. I'm the only one who's been in my store over a year other than my store manager. Im also about the only one who has a clue as to what I'm doing and can actually give advice. Its sad that a 20 year old has more know how than the other people I work with.
Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
any other alternators work? kevdeg16 General Technical & Electrical 6 12-30-2008 01:08 AM
can you rebuild alternators? colli360 General Technical & Electrical 1 04-11-2008 12:10 PM
All this talk of upgrading alternators jtfoxman General Technical & Electrical 58 10-10-2007 01:14 AM
Dual alternators DCRVP New Ideas 14 09-28-2007 01:37 PM
alternators BananaEdge General Technical & Electrical 10 10-20-2005 01:42 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 12:27 AM.


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 Amazon.com and affiliated sites.