Go Back   Ford Truck Enthusiasts Forums > Older, Classic & Antique Trucks > 1987 - 1996 F150 & Larger F-Series Trucks
Sign in using an external account
Register Forgot Password?


1987 - 1996 F150 & Larger F-Series Trucks 1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks

Welcome to Ford-Trucks Forums!
Welcome to Ford-Trucks.com.

You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the Ford-Trucks Forums community today!





 
Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 10-19-2014, 03:04 PM
focalized focalized is offline
New User
 
Join Date: Oct 2014
Posts: 3
focalized is starting off with a positive reputation.
Electrical issues with charging system, need help!

I put in a new battery and am sitting at 12.2. When starting the truck the alternator is putting out roughly 16.5, and the battery drops as low as 11.7 opposed to running at 13.* - 14.*

I have changed:
battery
alternator
starter
serpentine belt
starter solenoid
cleaned/changed terminals, ground contacts exc

Ive opened the fuse link on the alternator and it was fine.


Im at a loss and any help would be greatly appreciated. Ive been dealing with this for over a week and need to get back on the road.
Reply With Quote
  #2  
Old 10-19-2014, 03:17 PM
bashby's Avatar
bashby bashby is offline
Post Fiend
 
Join Date: Nov 2005
Location: Charles Town, W bygod Va
Posts: 6,007
bashby has a great reputation on FTE.bashby has a great reputation on FTE.bashby has a great reputation on FTE.bashby has a great reputation on FTE.bashby has a great reputation on FTE.
Can you clarify? You say you have 16v while starting?
Reply With Quote
  #3  
Old 10-19-2014, 03:25 PM
focalized focalized is offline
New User
 
Join Date: Oct 2014
Posts: 3
focalized is starting off with a positive reputation.
The new alternator is putting out a consistent 16.5v at all times (so was the old)
The battery when starting will drop to 12v<, with lights on itll go to 11.7
amp light has been on


I started out having the issue on the way home when radio and lights went out, and started felling sluggish. I did some work on the truck and took it out the next day only to make it a mile or two down the road. When i got out the battery was down to 6v. I jumped it and got home, it died again. I was thinking possibly the voltage regulator and changed out the alternator, i also changed out the new battery that apparently was dead. I put the new stuff in, did further testing and back to square one. I still have 16.5+v at the alternator, and lower then expected volts at the battery.
Reply With Quote
  #4  
Old 10-19-2014, 03:34 PM
bashby's Avatar
bashby bashby is offline
Post Fiend
 
Join Date: Nov 2005
Location: Charles Town, W bygod Va
Posts: 6,007
bashby has a great reputation on FTE.bashby has a great reputation on FTE.bashby has a great reputation on FTE.bashby has a great reputation on FTE.bashby has a great reputation on FTE.
So you have different voltages at the alt and battery? Sounds like the wire between the two is bad or a bad connection.
Reply With Quote
  #5  
Old 10-19-2014, 03:43 PM
SteelHorse4x4's Avatar
SteelHorse4x4 SteelHorse4x4 is offline
Senior User
 
Join Date: Sep 2013
Location: Virginia Beach/Wisconsin
Posts: 278
SteelHorse4x4 is starting off with a positive reputation.
Sounds like you may have gotten a bad alternator at the store. 16.5 is too high and I have seen alternators do that before. On these alternators when voltage increases current drops when the regulators go bad. I would take it to the parts store and have it bench tested.
__________________
1994 FlareSide SC 5.8 4x4 E4od LSD(Frt&Rear)


Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy; its inherent virtue is the equal sharing of misery. (Winston Churchill)
Reply With Quote
  #6  
Old 10-19-2014, 04:11 PM
rla2005's Avatar
rla2005 rla2005 is offline
Post Fiend
 
Join Date: Oct 2005
Location: Illinois
Posts: 8,064
rla2005 is a splendid one to beholdrla2005 is a splendid one to beholdrla2005 is a splendid one to beholdrla2005 is a splendid one to beholdrla2005 is a splendid one to beholdrla2005 is a splendid one to beholdrla2005 is a splendid one to behold
Quote:
Originally Posted by bashby View Post
So you have different voltages at the alt and battery? Sounds like the wire between the two is bad or a bad connection.
Ding, ding, ding! we have a winner
__________________
2013 Ford Taurus Limited 3.5L
2006 Ford Mustang GT 5-speed 3v 4.6L
rla2005@yahoo.com
Randy A | Central Illinois
Reply With Quote
  #7  
Old 10-19-2014, 05:37 PM
focalized focalized is offline
New User
 
Join Date: Oct 2014
Posts: 3
focalized is starting off with a positive reputation.
Quote:
Originally Posted by SteelHorse4x4 View Post
Sounds like you may have gotten a bad alternator at the store. 16.5 is too high and I have seen alternators do that before. On these alternators when voltage increases current drops when the regulators go bad. I would take it to the parts store and have it bench tested.
Its not the alternator, the one i just took out had the exact same reading, and hell i had that one tested 4 times :-p


Quote:
Originally Posted by bashby View Post
So you have different voltages at the alt and battery? Sounds like the wire between the two is bad or a bad connection.
I can try replacing the wire between the two and see. As of now ive only looked them over, cleaned harness, and all contacts. I was trying to find one at the junk yard but didnt have any luck, the one good one i found someone had already cut in half, the dealership no longer sells the wire/harnesses that go from the alternator to the starter solenoid.
Reply With Quote
  #8  
Old 10-19-2014, 05:45 PM
bashby's Avatar
bashby bashby is offline
Post Fiend
 
Join Date: Nov 2005
Location: Charles Town, W bygod Va
Posts: 6,007
bashby has a great reputation on FTE.bashby has a great reputation on FTE.bashby has a great reputation on FTE.bashby has a great reputation on FTE.bashby has a great reputation on FTE.
Id be looking closer at the fusible links. What year truck are we talking about? Is it internally regulted? The one with that rectangular plug that you are supposed to replace whenever its disconnected?
Reply With Quote
  #9  
Old 10-19-2014, 07:56 PM
NotEnoughTrucks2014 NotEnoughTrucks2014 is offline
Senior User
 
Join Date: Mar 2014
Location: Saskatchewan Canada
Posts: 147
NotEnoughTrucks2014 is gaining momentum as a positive member of FTE.
Quote:
Originally Posted by rla2005 View Post
Ding, ding, ding! we have a winner
Exactly and here is why.

The voltage at the battery and the voltage at the alternator should be exactly the same, well at least much closer than 12.2V and 16.5V. Question now is where exactly are you measuring this? Between battery posts? Chassis ground or engine block? Alternator output stud?

Here is a further test you may want to do. Measure voltage between the battery negative post and chassis ground. Do the same for the battery negative to the engine block. Any voltage reading means you have a problem with grounds. Now check voltage between the battery positive post and the alternator output post. If there is any significant voltage, you have a wiring problem between the alternator and the battery. You may see a small reading like 0.1V, but this will likely be within the margin of error in your meter. If your numbers are correct, you should see 4.1V somewhere in this circuit and that will pinpoint the fault.
Reply With Quote
  #10  
Old 10-20-2014, 05:27 AM
ArdWrknTrk's Avatar
ArdWrknTrk ArdWrknTrk is offline
<---Dog is my co-pilot
 
Join Date: Jan 2008
Location: EXTREME southwest CT
Posts: 18,694
ArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputation
Likely a 2G alternator and the infamous 'Fire Plug' has gone bad.
There is no output stud on these...
(he mentions changing the alternator because he felt the -internal- regulator had gone bad)
If the alternator's regulator does not 'sense' output voltage, the alternator will go full field trying to charge the system.

To the OP,
Disconnect the rectangular three wire plug with two orange/black and a white/black wire from the alternator.
Check for continuity between the plug and the starter solenoid stud.
Look to see if the plastic plug has melted internally.

Ford's TSB for 2G charging problems outlines that any time the charging system is worked on this plug pigtail needs to be replaced.
In fact, most alternator manufacturers/rebuilders won't warranty unless it has, and include it in the box.
Almost every aftermarket wiring company makes this pigtail.
__________________
Jim (AKA Princess Glitzhooter)
'87 F-250
460, 4V 0-80457s, Edelbrock Intake, Saginaw PS Pump, BW 1356 4x4, 4.10 10.25", 130A 3G Alt., PMGR starter, ZF-5, - Lil' Red
http://i246.photobucket.com/albums/gg117/donjamer/FTE%20Pics/blumax500-1-1.jpgFTE Fraternity of Blue Max
Reply With Quote
  #11  
Old 10-20-2014, 05:42 AM
dixie460's Avatar
dixie460 dixie460 is offline
Posting Guru
 
Join Date: Nov 2011
Location: SW Florida
Posts: 1,854
dixie460 has a good reputation on FTE.dixie460 has a good reputation on FTE.
Quote:
Originally Posted by ArdWrknTrk View Post
If the alternator's regulator does not 'sense' output voltage, the alternator will go full field trying to charge the system.
Exactly. That right there is your clue. Agreed about the "fire plug" being faulty... the OP will probably find it all nice and crispy inside when he pulls it apart.
__________________
96 F-150 SCSB - 351W - Rebuilt E4OD - Manual 1356 T-Case Swap - 3.55 Gears - 31x10.50x15 Falken WildPeaks - York 210 OBA - 130A Alternator - MileMarker Supreme Lockouts - Badlands 12K Winch - Dual Thrush Glasspacks - LED Headlight Conversion
Reply With Quote
  #12  
Old 10-20-2014, 05:57 AM
ArdWrknTrk's Avatar
ArdWrknTrk ArdWrknTrk is offline
<---Dog is my co-pilot
 
Join Date: Jan 2008
Location: EXTREME southwest CT
Posts: 18,694
ArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputation
Quote:
Originally Posted by focalized View Post
the dealership no longer sells the wire/harnesses that go from the alternator to the starter solenoid.
Refer to TSB #96214...
They don't sell it because it has been superseded by a repair kit.

Any of these brands should interchange, and be available locally for around $10.

Borg-Warner PT-780
Standard Motor Products S-542
Power Plug 4628011
KEM Parts 350-220
Pico 5711
Dorman 85123
Motormite 08622
NAPA VRA400
__________________
Jim (AKA Princess Glitzhooter)
'87 F-250
460, 4V 0-80457s, Edelbrock Intake, Saginaw PS Pump, BW 1356 4x4, 4.10 10.25", 130A 3G Alt., PMGR starter, ZF-5, - Lil' Red
http://i246.photobucket.com/albums/gg117/donjamer/FTE%20Pics/blumax500-1-1.jpgFTE Fraternity of Blue Max
Reply With Quote
  #13  
Old 10-20-2014, 08:32 AM
timbersteel's Avatar
timbersteel timbersteel is online now
Posting Guru
 
Join Date: Mar 2005
Location: Mexico, Missouri
Posts: 2,277
timbersteel is gaining momentum as a positive member of FTE.timbersteel is gaining momentum as a positive member of FTE.
If this is the notorious 2G alt, I would suggest doing the 3G alternator conversion.

I just did this conversion on my '92, 302 and pleased at the results. 2nd one now and my other '92, 4.9, I did 6 years ago.
__________________
1992 F-150 I6 4.9L 300 110K 4x4, SuperCab, Manual
1992 F-150 V8 302 156K 4x4, SuperCab, Auto
"He's one brick shy of a load..."
"These ideas, evaluations, opinions are representations of real-life scenarios and backed by Murphy's Law..."
"Inferior parts lead to immediate failure sooner than later..."
Reply With Quote
  #14  
Old 10-20-2014, 08:34 AM
ArdWrknTrk's Avatar
ArdWrknTrk ArdWrknTrk is offline
<---Dog is my co-pilot
 
Join Date: Jan 2008
Location: EXTREME southwest CT
Posts: 18,694
ArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputationArdWrknTrk has a superb reputation
We are ALL in the 3G club!
__________________
Jim (AKA Princess Glitzhooter)
'87 F-250
460, 4V 0-80457s, Edelbrock Intake, Saginaw PS Pump, BW 1356 4x4, 4.10 10.25", 130A 3G Alt., PMGR starter, ZF-5, - Lil' Red
http://i246.photobucket.com/albums/gg117/donjamer/FTE%20Pics/blumax500-1-1.jpgFTE Fraternity of Blue Max
Reply With Quote
  #15  
Old 10-20-2014, 10:09 AM
dixie460's Avatar
dixie460 dixie460 is offline
Posting Guru
 
Join Date: Nov 2011
Location: SW Florida
Posts: 1,854
dixie460 has a good reputation on FTE.dixie460 has a good reputation on FTE.
Yep, love my 130A 3G. Direct bolt-in replacement for the 95A 3G that was originally there.
__________________
96 F-150 SCSB - 351W - Rebuilt E4OD - Manual 1356 T-Case Swap - 3.55 Gears - 31x10.50x15 Falken WildPeaks - York 210 OBA - 130A Alternator - MileMarker Supreme Lockouts - Badlands 12K Winch - Dual Thrush Glasspacks - LED Headlight Conversion
Reply With Quote
Old 10-20-2014, 10:09 AM
 
 
 
Reply

Go Back   Ford Truck Enthusiasts Forums > Older, Classic & Antique Trucks > 1987 - 1996 F150 & Larger F-Series Trucks

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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Help with 79 F100 alternator not charging wsnead56 1973 - 1979 F-100 & Larger F-Series Trucks 24 09-05-2011 08:29 PM
99 f350 still drains batts alternator good Zephyrhills Ford 1999 - 2003 7.3L Power Stroke Diesel 44 08-04-2010 03:05 PM
Easy button imabaytiger Electrical Systems/Wiring 1 02-18-2006 07:19 PM
can't charge battery dan66tampa 1961 - 1966 F-100 & Larger F-Series Trucks 16 01-24-2005 09:20 PM
Need info about alternator wiring batmanincoralville 1987 - 1996 F150 & Larger F-Series Trucks 8 03-22-2004 11:22 AM



All times are GMT -5. The time now is 12:45 AM.


Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Advertising - Terms of Use - Privacy Statement - Jobs
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company.

vbulletin Admin Backup