heres a melon-tweaker...

[Caleb]

the other night i was driving home and i noticed my charge meter was reading over on the 'D' side, indicating that it was running off of the battery instead of charging, and giving it gas did not change the position of the needle. this has happened before and it turned out that my alternator field wire had come off. however, this was not the case this time. i pulled over and did a very thorough visual check of the entire charging system (battery, regulator, alternator) and everything was where it was supposed to be. i checked the alternator by sticking a pair of channel-locks behind it and making sure that the alternator was working because it was creating a magnetic field. So i went ahead and drove home, hoping that my battery would die and leave me driving down a little road in the dark without any headlights. i made it home and the next day i used an volt meter the make sure that everything was working properly. here are the findings.
-when the engine is idling and nothing electrical is engaged(lights, heater, wipers) there are 12 volts all the way from the battery through the regulator, to the alternator. the charge meter stays slightly to the 'D' side, even when i rev the engine.
-when the lights, heater, and wipers are turned on, the charge meter reads very far on the 'D' side, still with rpm's not affecting it. The battery reads 12 volts, but the regulator reads only 11.5, and so does the alternator. I replaced the regulator and still the same result.

I have checked and re-checked every wire related to the charging system and lights, all the way to the end of the pickup, and i found nothing that should be draining the system. I thought that the charge meter just may be going out, but im not sure. any suggestions?

[Jones]

Caleb,
Have you checked the grounding strap? Clean the contact it makes with the fire wall and the back of the motor where it bolt on the block. Make sure there's metal on metal. It may make a difference. Have you checked the brushes in the alt? Sometimes they too wear out...


Keith

[cowboy]

How old is the battery/ & is it a good brand as in not wal-mart auto zone i have them types almost new & go bad

[Caleb]

i just did the good ol' alternator test by pulling the (+) cable off the battery and seeing if the engine continues running and it did not, so it is in fact not charging. the alt isnt very old at all but i will check the brushes because it just may not be charging like it should

[Oldguy]

Iirc, there are 2 diodes in the alternator and you might have lost one. Seems that happened to me a while back but I've slept since then so don't remember for positive! LOL Good luck.

Mike

[dodgegrrrrrrl]

You answered your own question. If you have 11.5-12 volts at the battery your voltage is low, you field is reading low and consequently, your alt, is charging to the field voltage. You should be @ 13.2-13.7 at the battery.

My next suggestion was going to be "brushes" but you figgered that one out.

If anybody needs a newer alternator, from the 100AMP Mopars, (can be built to 200+ amps) 100 AMP Motorcrafts (can be built to 200 amp), the Bosch 76 amp , nipponsdenso (can be built to like 230 amp).....let me know. We have access to used and spec-built rebuilt and they beat the HELL out of the old Mopar 37-63 amp birdcages.