Notices
1999 - 2016 Super Duty 1999 to 2016 Ford F250, F350, F450 and F550 Super Duty with diesel V8 and gas V8 and V10 engines
Sponsored by:
Sponsored by: Real Truck

Fried Alternators

Thread Tools
 
Search this Thread
 
Old Sep 16, 2012 | 11:37 AM
  #1  
thejefe's Avatar
thejefe
Thread Starter
|
New User
Joined: Aug 2012
Posts: 9
Likes: 0
From: ne oklahoma
Fried Alternators

Whats the deal with these alternators going toast? I'm on my 4th in 2 weeks. Have an alternator shop that tells me I'm drawing too many amps. Tests normal amp draw at idle and 2000 rpm. noticed today alternator failed at high rpm 5000 or so, got the battery light and only 11.9 volts max on the scan gauge at any rpm.
 
Reply
Old Sep 16, 2012 | 01:29 PM
  #2  
Kdr358's Avatar
Kdr358
Postmaster
Joined: Jan 2012
Posts: 2,693
Likes: 3
From: West of Chicago
I'm assuming you have a gas motor based on the 5k rpms. Do you have any aftermarket electronics like subs or an amp? Also what brand alternator are you using. I suspect something is shorting out. How is your battery?
 
Reply
Old Sep 16, 2012 | 01:32 PM
  #3  
tjc transport's Avatar
tjc transport
i ain't rite
Joined: Mar 2005
Posts: 65,426
Likes: 5,507
From: Marlboro Mental Hospital.
Club FTE Gold Member
i had my local electrical shop build me a 200+ amp alternator when my stock 135 amp died because with the snow plow and all the lights on i am drawing rite around 160 amps.

it cost the same as buying a stock alternator from an auto parts store
 
Reply
Old Sep 16, 2012 | 04:23 PM
  #4  
thejefe's Avatar
thejefe
Thread Starter
|
New User
Joined: Aug 2012
Posts: 9
Likes: 0
From: ne oklahoma
Sorry bout that, Its a 2004 f250 5.4. have lights and elec fans on the radiator is all, no big amps. everything was turned off this last time anyway. have not checked current draw on the radiator fans. is there any known weak spot in the electric system? any common problems besides the alternator?
 
Reply
Old Sep 16, 2012 | 04:30 PM
  #5  
twags6's Avatar
twags6
Cargo Master
20 Year Member
Joined: Jan 2001
Posts: 2,726
Likes: 5
From: Slatington, PA
Club FTE Gold Member
Sounds like its time to find a new place to buy them. It sounds like your voltage regulators are crapping out. I had my original stocker and a second used stocker rebuilt at a local shop that has an excellent reputation. The guy even explained to me about some of the weak points these alternators have. Go with Tom's idea and have it rebuilt at a local shop that knows what they're doing.
 
Reply
Old Sep 16, 2012 | 04:41 PM
  #6  
Kdr358's Avatar
Kdr358
Postmaster
Joined: Jan 2012
Posts: 2,693
Likes: 3
From: West of Chicago
I also agree to find a shop to build one for your needs. FWIW my stock alt went 275,000 miles. My new autozone alternator is already getting weak after 5k miles. Glad I get a free lifetime replacement!
 
Reply
Old Sep 16, 2012 | 04:51 PM
  #7  
twags6's Avatar
twags6
Cargo Master
20 Year Member
Joined: Jan 2001
Posts: 2,726
Likes: 5
From: Slatington, PA
Club FTE Gold Member
That's why I had the stock one rebuilt! All that went was the regulator. He replaced the bearings, regulator and upgraded the diodes. They both still charged actually, but only above 1200rpms. Got nothing at idle. The lifetime warranties are nice, but it sucks having to replace one every year.
 
Reply
Old Sep 16, 2012 | 05:13 PM
  #8  
thejefe's Avatar
thejefe
Thread Starter
|
New User
Joined: Aug 2012
Posts: 9
Likes: 0
From: ne oklahoma
I have a starter generator shop that has repaired it for me twice. Only had to pay once. I don't think he ever replaced the voltage regulator. I'll have him do that this time.
On those weak alternators, that's usually blown diods
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

 Verdad Gallardo
story-1

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-2

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

 Brett Foote
story-3

2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

 Michael S. Palmer
story-4

10 Most Surprising 2026 Ford Truck Features!

 Joe Kucinski
story-5

Top 10 Ford Trucks Coming to Mecum Indy 2026

 Brett Foote
story-6

5 Best / 5 Worst Ford Truck Wheels of All Time

 Joe Kucinski
story-7

Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!

 Joe Kucinski
story-8

Every 2026 Ford Truck Engine RANKED from WORST to FIRST!

 Michael S. Palmer
story-9

The Best F-150 Deal of Every Trim Level (XL through Raptor)

 Joe Kucinski
Old Sep 17, 2012 | 06:24 AM
  #9  
redford's Avatar
redford
FTE Leadership Emeritus
25 Year Member
Liked
Loved
Community Favorite
Joined: Sep 2000
Posts: 23,174
Likes: 1,678
From: Stephensville WI
Club FTE Gold Member
How is your battery? Is it over 5 years old?
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
hi-jacker
1999 - 2016 Super Duty
7
Oct 1, 2018 07:27 PM
pack4tag
1999 - 2016 Super Duty
8
Mar 30, 2017 03:00 AM
ac700wildcat
1987 - 1996 F150 & Larger F-Series Trucks
39
Dec 16, 2010 02:48 AM
caddywhompus
1978 - 1996 Big Bronco
7
Dec 7, 2004 08:48 AM




All times are GMT -5. The time now is 07:31 AM.

story-0
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-1
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-2
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE
story-3
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Slideshow: Everything You Need to Know about the 2027 Super Duty Carhartt Package!

By Michael S. Palmer | 2026-05-07 17:51:06


VIEW MORE
story-4
10 Most Surprising 2026 Ford Truck Features!

Slideshow: 10 most surprising Ford truck options/features in 2026.

By Joe Kucinski | 2026-05-05 11:17:22


VIEW MORE
story-5
Top 10 Ford Trucks Coming to Mecum Indy 2026

Slideshow: Here are the top 10 Fords coming to Mecum Indy 2026.

By Brett Foote | 2026-05-04 13:49:49


VIEW MORE
story-6
5 Best / 5 Worst Ford Truck Wheels of All Time

Slideshow: The 5 best and 5 worst Ford truck wheels of all time

By Joe Kucinski | 2026-04-29 16:49:01


VIEW MORE
story-7
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!

Slideshow: Ranking the 5 things owners love about their Super Duty and 5 things they don't

By Joe Kucinski | 2026-04-29 16:36:49


VIEW MORE
story-8
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!

Slideshow: Ranking all 12 Ford truck engines available in 2026.

By Michael S. Palmer | 2026-04-22 13:32:20


VIEW MORE
story-9
The Best F-150 Deal of Every Trim Level (XL through Raptor)

Slideshow: The best Ford F-150 deal for every trim level (XL through Raptor)

By Joe Kucinski | 2026-04-21 15:59:01


VIEW MORE