Charging problem, need help.

[raymeg0]

I have 95 powerstroke. I was driving to work the other morning and lights went dim. I parked it and it died soon after and would not start. I had the batteries tested and the alternator tested. Alternator failed, batteries passed. The batteries aren`t that old. I replaced the alternator. Charged the batteries as long as I could,not a full charge though. I got the truck running so i could get it home. It still did the same thing on the drive back home. I checked the voltage from the alrernator at the big hot wire with the screw terminal and it read 20 volts. I have the batteries on a slow charge as wee speak. What am I missing?

[thesmokinstroke02]

thats a weird situation. im not sure myself but heres a

[lifewitlooie]

see if it happens after a full charge again. I have had 2 reman alternators go out on me, one after another. Now I am on the third with no problems after many months.

[raymeg0]

Say the batteries were bad, wouldnt the alternator still keep the lights and so forth powered up when the truck was running?

[krazeehorse]

Check your voltage at the battery terminals when it's running. Should be 14-15. You may have to bring the revs up a little off idle but not very much to see this voltage.

[raymeg0]

There`s no voltage change while its running. Even when you raise the rpms.

[raymeg0]

did anybody notice the fact that the alt. is putting out 20 volts? Heres what i did today; I charged the batteries all night on 2 amps. I checked them when I got home from work and they were at around 12.5 volts. truck started fine. The batteries dropped down to 11.90 after it was running. I checked the voltage at the alternator and it was up around 22 volts. What do you guys think? Does it sound like a bad voltage regulator in the new alternator? All this craps gonna ruin my batteries .

[forddieseldoctor]

hmm sounds like a bad alternator. i had it happen on my brother's f150. you should be able to take it off and take it in and have it tested at your local autoparts store.

[ono_55]

At 22volts you are going to fry something!

[n3msk]

Originally Posted by raymeg0

did anybody notice the fact that the alt. is putting out 20 volts? Heres what i did today; I charged the batteries all night on 2 amps. I checked them when I got home from work and they were at around 12.5 volts. truck started fine. The batteries dropped down to 11.90 after it was running. I checked the voltage at the alternator and it was up around 22 volts. What do you guys think? Does it sound like a bad voltage regulator in the new alternator? All this craps gonna ruin my batteries .

Sounds like the wire from the alternator to the battery may be bad.