1999 Ford Mustang will not charge battery

Tiny
MARK KUHN
  • MEMBER
  • 1999 FORD MUSTANG
  • 6 CYL
  • 2WD
  • MANUAL
  • 105,000 MILES
Have replaced with new battery. Have replaced altenator (thought it ws bad took it back and exchanged for another). SO new altenator; new battery. Altenator will not charge battery. Have replaced battery terrminals. Battery light stays on at dash and car runs off battery until it discharges. No voltage difference (stays at 12.5v) with car at 2000 RPM. What else is there? The only thing I can think of is to replace the ground cable amd the hot cable or the wiring between the altenator and the fuse box. Next Check the ground strap from the engine to the chassis. Could it be the hot lead going to the voltage regulator? It is the 3 pronged lead with the middle lead going to a fourth pin (i read nothing on that lead with volt meter). ALso the altenator has bench tests good.
Do you
have the same problem?
Yes
No
Monday, August 25th, 2008 AT 11:27 AM

5 Replies

Tiny
BLACKOP555
  • EXPERT
Check to make sure the alternator is hooked up properly and all cables are clean of corrosion. Check the wiring harness for damage also, get back to me.
Was this
answer
helpful?
Yes
No
Monday, August 25th, 2008 AT 1:14 PM
Tiny
MARK KUHN
  • MEMBER
Thanks. I did all that up top. I have not gotten under the car and checkec the other ends. I even scraped teh terminal fittings. It seems to me that for some reason the voltage regulator is not geetting a signal that the battery needs charging. There are three leads going into hte voltage regulator. What kind of voltage or ground should I be seeing on those leads. I know the middle lead goes over to a 4th terminal right next to the 3 lead connector. As far as the large cables I even replaced the connectors on the ground and posative.
Was this
answer
helpful?
Yes
No
Monday, August 25th, 2008 AT 3:15 PM
Tiny
BLACKOP555
  • EXPERT
For some reason my online diagrams arnt loading tonight, you will have to remind me tomorrow to look for them!
Was this
answer
helpful?
Yes
No
Monday, August 25th, 2008 AT 8:00 PM
Tiny
MARK KUHN
  • MEMBER
OK! I should have worn glasses! The problem was no voltage on the yellow lead going to the voltage regulator. Stripped and cut the wire into. Traced it with a toner. Went to the fuse box. Found the fuse. IT WAS BLOWN. I chedcked those fuses 6 days ago(twice) and did NOT appear to be blown. My son came out last night and checked the fuses with a toner and fond the blown fuse. I expalined I checked them. He asked if I was wearing my glasses. NOooo!

All is well except for an embarrased dad.

Thanks, so much for your help.
Was this
answer
helpful?
Yes
No
Tuesday, August 26th, 2008 AT 11:02 AM
Tiny
BLACKOP555
  • EXPERT
Ouch! I hate it when that happens but then again you could have blew it when you replaced the alternator or battery after you had checked it! Remember that!

Glad to hear it was a simple 15 cent fuse
Was this
answer
helpful?
Yes
No
Tuesday, August 26th, 2008 AT 11:06 AM

Please login or register to post a reply.

Recommended Guides