1968 Ford Pick-up

68,000 MILES • V8 • 2WD • AUTOMATIC
Avatar
SMOOTHLUV
  • MEMBER
  • 1 POST
I replaced my alternator and voltage regulator brand new, and I cannot get my truck to run off the alternator, it only runs on the battery, every time I discconect the positive from the battery my truck dies. Can you please help me?
Mar 22, 2011 at 3:04 PM
Advertisement
Avatar
RASMATAZ
  • ✓Experienced Mechanic
  • 75,988 POSTS
Disconnect the voltage regulator and jumper A to F on the connector if it starts charging -replace the regulator
Mar 22, 2011 at 5:13 PM
Avatar
CARADIODOC
  • ✓Experienced Mechanic
  • 34,413 POSTS
Removing the battery cable is a REAL bad idea on newer vehicles with computers because if the generator is working, the excessive voltage can destroy them. You won't have any trouble on a '68 model, but there's a better test. Use an inexpensive digital voltmeter to measure battery voltage while the engine is running. It should measure between 13.75 and 14.75 volts. If it stays near 12.0 to 12.6 volts suspect the generator or voltage regulator. I have to do this from memory: If there are four wires on the voltage regulator, look for terminals "A" and "F". I think those are on the two ends of the connector but look for those letters to be sure. Remove the plug, then use a piece of wire to connect those two terminals. If the voltage goes up, replace the regulator. If there is no change, suspect the generator.
Mar 22, 2011 at 5:17 PM
Avatar
CJ MEDEVAC
  • ✓Experienced Mechanic
  • 11,000 POSTS
Many times on a Ford, the connector for the Voltage Regulator gets sorta bent or warped. Insure the contacts are clean (pencil eraser may help) and making contact.--The Medic
Mar 22, 2011 at 6:41 PM
Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Frequently Asked Problems for This Vehicle