Alternator not charging

Tiny
LARIATCREW04
  • MEMBER
  • 2004 FORD F-150
  • V8
  • 4WD
  • AUTOMATIC
  • 75,000 MILES
I have a 2004 F150 with 75k and today when I tried to start it in the cold it just clicked and the horn started going off. Everytime I closed the door the horn would start going off. I got a jump took it to Wal-Mart and changed the batter but it would not start and it would continue to honk. It was a blizzard and I was trying to get it going for 2 hours. I finally got it but on the way home, it said to check battery and it said it was not recharging. I would say it was the alternator but it did not do this earlier and I did change it while it was snowing because I had no other choice. Please let me know if you have any answers.
Do you
have the same problem?
Yes
No
Wednesday, December 9th, 2009 AT 12:16 AM

41 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
It sounds like you have the same type of luck that I do. Have you had any other problems since you replaced the alt?

This guide can help

https://www.2carpros.com/articles/how-to-check-a-car-alternator

and

https://www.2carpros.com/articles/how-to-replace-an-alternator

Please run down this guide and report back.

Was this
answer
helpful?
Yes
No
Thursday, December 10th, 2009 AT 10:49 AM
Tiny
JIMMYB1966
  • MEMBER
  • 2000 FORD F-150
  • V8
  • 4WD
  • AUTOMATIC
  • 113,000 MILES
Hello my name is Jim, my problem is alternator. My battery light came on on dashboard of my 2000 f-150, I went to autopart store and they tested my alternator to find out it was bad (diodes)i bought a new alternator and put it in. Battery light went off for three days of driving and then came back on.I went back to the store and they checked it again to find out it had a charging problem they said check the wires to make sure all are tight if so take alt. Out bring it back and they will give me a new one. Is it posible my charging system did somthing to the previous alternator or did I get a defective one to begin with? Should I be cousios with puting in another alternator? Also have new battery.
Was this
answer
helpful?
Yes
No
Monday, June 29th, 2020 AT 12:48 PM (Merged)
Tiny
FLEXY5
  • MEMBER
Did you replace the battery at the same time as the altermator, before, or after? Did they test the battery also? On rare occasions, I have seen an alternator go bad and take out the battery. A bad battery could cause new alternators to burn out as well. Have them tested seperately.
Was this
answer
helpful?
Yes
No
Monday, June 29th, 2020 AT 12:48 PM (Merged)
Tiny
ANTHONYMIRANDA
  • MEMBER
  • 1998 FORD F-150
  • V8
  • 4WD
  • AUTOMATIC
  • 176,000 MILES
My battery is not charging. I have replaced the battery, alternator and battery fuse. What else could I check?
Was this
answer
helpful?
Yes
No
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
2CEXPT
  • MEMBER
Check all the fuses below if okay start testing the wires/connectors for looseness, open and short circuit


https://www.2carpros.com/forum/automotive_pictures/12900_fuses_13.jpg

Was this
answer
helpful?
Yes
No
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
JBNY
  • MEMBER
  • 1997 FORD F-150
  • 6 CYL
  • 2WD
  • MANUAL
  • 137,000 MILES
New battery will not charge. New alt/reg did not solve problem. During testing, grounding the regulator proved 18 volts from alternator. New regulator and known good regulator all act the same.
At one point, grounding the regulator would make the system work properly until engine was shut down. This no longer happens.
Followed testing procedures laid out in Haynes manual and everything says replace regulator. Does not fix problem
Was this
answer
helpful?
Yes
No
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
WRENCHER1
  • MEMBER
Follow the orange with lt. Blue wire from the alternator and look for a 20amp inline fuse and check that.
Also check all the fuses in the under dash fuse box. There is a 10amp fuse there associated with the alternator but I don't know what it's labeled. Use a test light to check them all for power at both ends with the key on.
Was this
answer
helpful?
Yes
No
+2
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
JBNY
  • MEMBER
The mini fuse is intact as well as all the fuses in the circuit. Power is where it's supposed to be and grounds are intact. The alternator puts out 18 volts when the IAR is grounded at the test point.

Wiggle tests showed no irregularities and I'd rather not be opening the harness unless I have to. The circuit is fairly simple with only a clutch interrupt switch and ignition switch involved. I get the feeling this is a unique problem and am totally stumped as to how to proceed.

Being able to ground the IAR and have the system work properly is really throwing me, especially since now it no longer does that. This is making absolutely no sense.

BTW-thanks for responding. I was an ASE certified Ford wrench for ten years specializing in EECIV systems and driveability. I've never run across this.
Was this
answer
helpful?
Yes
No
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
WRENCHER1
  • MEMBER
If you don't want to listen I'll just go help someone else. Good luck.
Was this
answer
helpful?
Yes
No
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
JBNY
  • MEMBER
Did I miss something about what you said? The org/lt blue wire runs to the fuse you mentioned and turns into a yel/wht wire. Continuity checks and voltage drop checks all show normal. All fuses were checked after your advice with no irregularities, including those in the power distribution box.
Was this
answer
helpful?
Yes
No
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
WRENCHER1
  • MEMBER
I'm sorry. I got the impression you disagreed and blew off the checks.

The alternator is a self contained unit so if all the inputs and outputs are correct, then it has to charge, assuming the alternator is good.

Verify power coming in on the orange/lt blue and the lg/red with the key one. Verify there power at the main terminal with the key off and that the alternator is grounded.
Was this
answer
helpful?
Yes
No
+1
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
RIGIDCFLMAN@YAHOO.COM
  • MEMBER
  • 1997 FORD F-150
  • V8
  • 4WD
  • AUTOMATIC
  • 157,000 MILES
After my third altenator and second battery my truck will not charge just runs till dead. Traced the wiring harness from volt reg to power box no bad wires I can see.175 amp mega fuse is good. All other fuses are good as well
Was this
answer
helpful?
Yes
No
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
JBNY
  • MEMBER
No it's my turn to apologize for the negative feedback I gave after your snarky response.

There is no power on the lt grn/red wire with KOEO. A test vehicle right beside this one confirms there should be. This line comes from the instrument panel charge indicator so I believe you've given me a direction to go in. I will be back after I trace the wire backwards from the alternator.

What is your experience with where I might find the problem in the circuit?

TY again.
Was this
answer
helpful?
Yes
No
+1
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
SATURNTECH9
  • MEMBER
Could I please get the 8th digit of your vin number so I can get you the correct information. Sound's like a wiring issue though I wouldn't think you could get that many bad alternators in a row but anything is possible. Did you have the alternator's tested before you left the store?Also do you have a multimeter to do some testing?
Was this
answer
helpful?
Yes
No
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
WRENCHER1
  • MEMBER
Green red comes from the fuse in the dash box through the charge light in the dash so it could be interrupted at the back of the cluster. It's white/yellow from the fuse to the light.
Was this
answer
helpful?
Yes
No
+1
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
CARADIODOC
  • EXPERT
Measure the voltages on the wires that plug into the generator. Yellow must have 12 volts all the time. Green / red should have around 2.0 volts and the battery light should be on.
Was this
answer
helpful?
Yes
No
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
JBNY
  • MEMBER
It's even simpler than that. You'll get a kick out of this. When I checked the fuses in the fuse box earlier today I physically took each one out and looked at it. Then your advice got me back there checking again with the same results-everything's OK.

Rather than yank the cluster out I went to the fuse box again and was going to work up from there. Well, the 5 amp mini fuse in the circuit (#19)was still OK BUT when I put it back earlier I put it in the slot above where it was supposed to go. DOH!-I boned myself. Your check at the IAR connector is what got me there and I can't thank you enough.

How do I get you $ for this-you certainly earned it?
Was this
answer
helpful?
Yes
No
+3
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
RIGIDCFLMAN@YAHOO.COM
  • MEMBER
Saturntech9 my eighth digit is a W and yes I have a meter
Was this
answer
helpful?
Yes
No
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
WRENCHER1
  • MEMBER
Glad you found it.

I don't need money but if you can leave another positive or fix the feedback it would be nice. I don't even know if that is possible.
Was this
answer
helpful?
Yes
No
+2
Monday, June 29th, 2020 AT 12:49 PM (Merged)
Tiny
SATURNTECH9
  • MEMBER
Alright with the key in the run position at the alternator you should have battery voltage at the yellow wire with a white tracer. The orange wire with a light blue tracer. So what is the voltage at the battery with the engine idling?Is the battery light on?Let me know what you find.
Was this
answer
helpful?
Yes
No
Monday, June 29th, 2020 AT 12:49 PM (Merged)

Please login or register to post a reply.

Sponsored links