Notices
1994.5 - 1997 7.3L Power Stroke Diesel  

Alternator ?

Thread Tools
 
Search this Thread
 
Old Sep 25, 2012 | 07:54 AM
  #1  
fordpride's Avatar
fordpride
Thread Starter
|
Post Fiend
Joined: Dec 2009
Posts: 15,505
Likes: 18
From: Livoina,La
Alternator ?

My voltage is dropping to 11.7-12.3v at idle and as soon as I touch the go pedal it jumps up to 14.5

Is the alternator gone or is it the voltage regulator ?
 
Reply
Old Sep 25, 2012 | 09:16 AM
  #2  
mojoman's Avatar
mojoman
Senior User
Joined: Aug 2006
Posts: 365
Likes: 0
give the alt casing a tap with a small hammer then check again at idle...hth
 
Reply
Old Sep 25, 2012 | 11:38 AM
  #3  
Talyn's Avatar
Talyn
Hotshot
20 Year Member
Community Favorite
Joined: Oct 2003
Posts: 17,791
Likes: 99
From: Ashland City, TN
Originally Posted by fordpride
My voltage is dropping to 11.7-12.3v at idle and as soon as I touch the go pedal it jumps up to 14.5

Is the alternator gone or is it the voltage regulator ?
Regulator is probably starting to fail.

I kept my old alternator to someday replace the regulator to have a spare.
 
Reply
Old Sep 25, 2012 | 12:35 PM
  #4  
stainlessstroker95's Avatar
stainlessstroker95
Postmaster
Joined: May 2011
Posts: 3,447
Likes: 0
From: Monroe City in
Interesting. Mind is doing that also, but my alt and batterys are only a year and a half old. The alt is from a shop around here not a parts store one. Of course i did let my truck sit for a while this summer whith out starting it much, maybe that had some thing to do with it.
 
Reply
Old Sep 25, 2012 | 07:02 PM
  #5  
fordpride's Avatar
fordpride
Thread Starter
|
Post Fiend
Joined: Dec 2009
Posts: 15,505
Likes: 18
From: Livoina,La
Any way to test the regulator?
 
Reply
Old Sep 25, 2012 | 07:03 PM
  #6  
fordpride's Avatar
fordpride
Thread Starter
|
Post Fiend
Joined: Dec 2009
Posts: 15,505
Likes: 18
From: Livoina,La
On a side note I noticed today the the top tank on my Rad. Is about to blow out. I'll post a pic later. FML
 
Reply
Old Sep 25, 2012 | 07:06 PM
  #7  
427 fordman's Avatar
427 fordman
Hotshot
15 Year Member
Photogenic
Photoriffic
Joined: Feb 2009
Posts: 10,408
Likes: 75
From: Plankinton, SD
Originally Posted by fordpride
On a side note I noticed today the the top tank on my Rad. Is about to blow out. I'll post a pic later. FML
That sucks. Sounds like me, more than one thing has to happen at once..
 
Reply
Old Sep 25, 2012 | 08:11 PM
  #8  
Hussler's Avatar
Hussler
Postmaster
Joined: Sep 2007
Posts: 4,195
Likes: 6
From: Medford Oregon
Club FTE Silver Member

Originally Posted by fordpride
My voltage is dropping to 11.7-12.3v at idle and as soon as I touch the go pedal it jumps up to 14.5

Is the alternator gone or is it the voltage regulator ?
Hard to say. When mine was doing that a few years ago I pulled the alternator and removed the regulator .. few bolts on the back and you can wiggle it out and the brushes come out with it. If the brushed are gone you can get those separate. In my case the brushes were fine.

Here is what the guts look like inside where the brushes sit and don't be afraid to pull it and look ...



IMO the slots where the brushes sit were worn down too much so I put it all back together, the auto store tested the alternator output, and told me it was good because it was outputting 12.5 volts. I told them they were nuts because our Ford alternators needed an output of 14+ volts.

Long story short, got a new alternator and all is well since.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-1

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

 Brett Foote
story-2

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

 Michael S. Palmer
story-3

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

 Verdad Gallardo
story-4

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-5

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

 Brett Foote
story-6

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

 Michael S. Palmer
story-7

10 Most Surprising 2026 Ford Truck Features!

 Joe Kucinski
story-8

Top 10 Ford Trucks Coming to Mecum Indy 2026

 Brett Foote
story-9

5 Best / 5 Worst Ford Truck Wheels of All Time

 Joe Kucinski
Old Sep 25, 2012 | 08:19 PM
  #9  
fordpride's Avatar
fordpride
Thread Starter
|
Post Fiend
Joined: Dec 2009
Posts: 15,505
Likes: 18
From: Livoina,La
Thanks Jim I'm just gonna replace the Atl. This weekend

But here's my other issue. It's all the way across the top tank
 
Reply
Old Sep 25, 2012 | 08:26 PM
  #10  
ReBilld's Avatar
ReBilld
Hotshot
10 Year Member
Joined: Jan 2012
Posts: 11,132
Likes: 3
From: Southern West Virginia
Yeah, that's not good!
 
Reply
Old Sep 25, 2012 | 08:27 PM
  #11  
fordpride's Avatar
fordpride
Thread Starter
|
Post Fiend
Joined: Dec 2009
Posts: 15,505
Likes: 18
From: Livoina,La
I got a really good rad shop here so I'm gonna see about getting the tank replaced.

What do y'all think it'll cost?
 
Reply
Old Sep 25, 2012 | 08:52 PM
  #12  
ReBilld's Avatar
ReBilld
Hotshot
10 Year Member
Joined: Jan 2012
Posts: 11,132
Likes: 3
From: Southern West Virginia
Aww, just go ahead and spend some of that old moldy money and get an all aluminum radiator! LOL!!
 
Reply
Old Sep 25, 2012 | 09:01 PM
  #13  
stainlessstroker95's Avatar
stainlessstroker95
Postmaster
Joined: May 2011
Posts: 3,447
Likes: 0
From: Monroe City in
i had booth tanks on my old car replaced a while back and it was around 100 bucks. Like bill said this is a good excuse to upgrade!
 
Reply
Old Sep 25, 2012 | 09:04 PM
  #14  
fordpride's Avatar
fordpride
Thread Starter
|
Post Fiend
Joined: Dec 2009
Posts: 15,505
Likes: 18
From: Livoina,La
Y'all trying to cut into my turbo fund. Lol
 
Reply
Old Sep 25, 2012 | 09:10 PM
  #15  
BuckHammer's Avatar
BuckHammer
Cargo Master
10 Year Member
Liked
Loved
Community Favorite
Joined: Jul 2010
Posts: 3,014
Likes: 115
Club FTE Silver Member

Originally Posted by ReBilld
Aww, just go ahead and spend some of that old moldy money and get an all aluminum radiator! LOL!!
YMMV, but the only components on my truck that are not corroded are the plastic ones.
 
Reply



All times are GMT -5. The time now is 10:44 AM.

story-0
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-1
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-2
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-3
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-4
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-5
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-6
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-7
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-8
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-9
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