Notices
1994.5 - 1997 7.3L Power Stroke Diesel  

Charging Problems

Thread Tools
 
Search this Thread
 
Old Nov 21, 2016 | 07:53 PM
  #1  
williameub's Avatar
williameub
Thread Starter
|
Senior User
Joined: Aug 2013
Posts: 244
Likes: 0
Charging Problems

I've been having a charging issue I can't seem to figure out.

While driving my volt gauge will show around 14V then fall to 9-10V every so often. Sometimes it'll never return back to charging. All the lights dim when this happens also.

At first, I figured it was either the Alt going bad or the glow plug relay clicking on causing a draw. I wired an led into the relay to see if that was the cause of my problem. It wasn't, so I went ahead and replaced the alternator.

Now my problem persists. I've hooked a multimeter onto the alt to see if the charge drops when I start pulling, pushing and jiggling wires. I couldn't get it to do anything.

Where do I go from here and what else can I check?
 
Reply
Old Nov 21, 2016 | 10:36 PM
  #2  
Bubba Jones's Avatar
Bubba Jones
Fleet Mechanic
15 Year Member
Joined: Dec 2006
Posts: 1,925
Likes: 10
From: Phoenix, AZ
Hmm, I can think of a few things that you may want to look into.

Since your alternator is new and you know your glow plugs aren't causing the draw, it might be possible that your belt is getting worn or starting to slip.

I'd check the serpentine belt to make sure it isn't excessively worn and also make sure no oil/ps fluid or liquids of any kind are spilling on the belt. It's possible the belt tensioner could be worn as well, but I've actually never heard of that happening.

Apart from that, I'd look over your battery connections (both positive connections and both ground connections) and also look at the charging cable from the alternator to the batter as well. If those connections are loose and or corroded, I could see if causing issues like you are having.
 
Reply
Old Nov 21, 2016 | 11:25 PM
  #3  
williameub's Avatar
williameub
Thread Starter
|
Senior User
Joined: Aug 2013
Posts: 244
Likes: 0
Originally Posted by Bubba Jones
Hmm, I can think of a few things that you may want to look into. Since your alternator is new and you know your glow plugs aren't causing the draw, it might be possible that your belt is getting worn or starting to slip. I'd check the serpentine belt to make sure it isn't excessively worn and also make sure no oil/ps fluid or liquids of any kind are spilling on the belt. It's possible the belt tensioner could be worn as well, but I've actually never heard of that happening. Apart from that, I'd look over your battery connections (both positive connections and both ground connections) and also look at the charging cable from the alternator to the batter as well. If those connections are loose and or corroded, I could see if causing issues like you are having.
Thanks for the reply. The slipping belt came to mind, but that isn't the cause. The belt looks perfect and I put a new tensioner on with the new alternator.

Battery connections I'll check tomorrow morning. I looked over the connections from the alt to the starter relay and from the relay to the battery. I tugged on them and made sure they where all tight whenever I was doing my testing this evening.

The ground strap at the back of the passenger head is torn, but has been since I bought the truck three plus years ago. I'll finally replace that tomorrow.
 
Reply
Old Nov 22, 2016 | 07:59 AM
  #4  
BuddyBarnes's Avatar
BuddyBarnes
Laughing Gas
5 Year Member
Liked
Loved
Community Favorite
Joined: Jan 2016
Posts: 910
Likes: 96
From: Fl.
These readings with factory gauge or after market? No # on factory gauge so I am thinking after market. If so check wire connections there too.
 
Reply
Old Nov 22, 2016 | 08:30 AM
  #5  
knottyrope's Avatar
knottyrope
Lead Driver
10 Year Member
Photogenic
Shutterbug
Loved
Joined: Apr 2016
Posts: 7,172
Likes: 1,332
From: Bahstun
https://www.ford-trucks.com/forums/1...ou-cranky.html


I made a thread of my cure which should help
 
Reply
Old Nov 22, 2016 | 10:35 AM
  #6  
fordpride's Avatar
fordpride
Post Fiend
Joined: Dec 2009
Posts: 15,505
Likes: 18
From: Livoina,La
Check the little plug on the alternator
 
Reply
Old Nov 22, 2016 | 04:45 PM
  #7  
williameub's Avatar
williameub
Thread Starter
|
Senior User
Joined: Aug 2013
Posts: 244
Likes: 0
Here's an update on the problem.

I unhooked both batteries and check voltage. Both read 12.9Vs. I know this doesn't rule them out just just. Need to have them load tested.

I also replaced the plug that plugs into the top of the alt.


Something I find odd is the Battery Light hasn't come on whenever it happens. There's an obvious drop in voltage but I don't know what's causing it. It's driving me crazy
 
Reply
Old Nov 23, 2016 | 08:57 AM
  #8  
knottyrope's Avatar
knottyrope
Lead Driver
10 Year Member
Photogenic
Shutterbug
Loved
Joined: Apr 2016
Posts: 7,172
Likes: 1,332
From: Bahstun
odd, I don't see OP last reply.


edit now I do after I replied


Maybe you have a loose ground some where


Should be one on each side of cab near kick panels


back of engine to cab
 
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 Nov 24, 2016 | 06:07 AM
  #9  
Shawn MacAnanny's Avatar
Shawn MacAnanny
Elder User
Joined: Dec 2005
Posts: 776
Likes: 3
From: Felton, Delaware
Funny, this happened to me last night on my way back from a jobsite, 70 miles away my cts2 was showing a drop to 11.9 to 12.1v. No check engine light, no voltage light I just saw low voltage on my tuner display and factory gauge showed needle around N. It's usually 13.9 to 14.2. I knew it wasn't serpentine belt since PS and brakes were there so I kept driving the next 20 miles to autozone so atleast I'd have some parts I could throw at it.

I checked over all connectors at the top and decided I'd remove the alternator to have it checked, went to remove the stud from the back of the alternator and found the lug on the wire had broken off and was barely touching the stud the rubber boot was over it and the shape of the wire was keeping it barely touching. I crimped a new lug on and it fixed it all.

Maybe the charging wire is chaffed somewhere or the terminal where is connects to relay is damaged
 
Reply
Old Nov 25, 2016 | 01:49 PM
  #10  
williameub's Avatar
williameub
Thread Starter
|
Senior User
Joined: Aug 2013
Posts: 244
Likes: 0
I think I finally fixed my problem. I started tracing the wires from the alt. back through th harness. I found a spot where some one has tried to repair it at one time and the repair had failed causing them to touch.
 
Reply
Old Nov 25, 2016 | 06:57 PM
  #11  
williameub's Avatar
williameub
Thread Starter
|
Senior User
Joined: Aug 2013
Posts: 244
Likes: 0
Update : That DIDNT fix my problem. I have found however that whenever this happens all four pins on the GPR have 12Vs... Idk where to go from here.
 
Reply
Old Nov 25, 2016 | 10:07 PM
  #12  
z31freakify's Avatar
z31freakify
Hotshot
10 Year Member
Liked
Loved
Community Favorite
Joined: Dec 2012
Posts: 11,266
Likes: 1,649
From: Las Cruces New Mexico
Gpr is toast, or maybe the wire running to the pcm is grounding itself somewhere in the harness.
 
Reply
Old Nov 25, 2016 | 10:38 PM
  #13  
williameub's Avatar
williameub
Thread Starter
|
Senior User
Joined: Aug 2013
Posts: 244
Likes: 0
Originally Posted by z31freakify
Gpr is toast, or maybe the wire running to the pcm is grounding itself somewhere in the harness.
Thanks! I'll trace that wire tomorrow.
 
Reply
Old Nov 26, 2016 | 02:06 AM
  #14  
jle70's Avatar
jle70
Senior User
20 Year Member
Joined: Oct 2003
Posts: 351
Likes: 1
From: Sullivan, IL USA
I had similar issue a few years ago. It ended up being a bad ground cable from RH battery. Just something to check.
 
Reply
Old Dec 14, 2016 | 09:29 PM
  #15  
williameub's Avatar
williameub
Thread Starter
|
Senior User
Joined: Aug 2013
Posts: 244
Likes: 0
I'm at a loss.

I've tried disconnecting the GPR, new belt and tensioner, new alt., cleaning all the terminals, cleaning the grounds and tightening them. Even added a block to frame ground strap and nothing is seeming to help.

The problem is getting worse too.

Any ideas?
 
Reply



All times are GMT -5. The time now is 12:34 PM.

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