The Volt meter on my 84 hatchback started to slip slowly from around 12 down to 8 volts about a month ago. I put an extra one I got from a friend in and the meter showned 12. In the last couple of weeks, the number has been slowly slipping again. If I don't drive the car for a couple of days, it will start showing about 11 again but as the a day of driving goes on, it slips to 8. Sometimes randomly it jumps up to 12 again but slowly comes down again. Any Ideas?

Thanks

-Max

I would suggest testing and/or replacing the Alternator. Make sure to fully charge, and load test the battery before running a new alternator. If not you can kill your'e new alt very quickly.

And if the parts stores do free testing in your area, have your units tested esp if you want to put on a used one-a bad diode or 2 can really cut down on the output and even drain your batteery under the right conditions.