good alternator, but still no charge
 

Hey, this is my first post ever. I thought this would be a great place to get an answer.
-I have an 88 Accord lxi 2-door, I have been driving it for about a year now and lately it hasn't been holding a charge. I'll plug it into a charger, drive it for about 3 days (with no problems), then it will be dead. It has a napa alternator, and I've heard form several people that napa has bad alternators. Could this be a problem with the ground? I just need to find the leak. I had the alternator tested twice and it passed both times.
Thanks

RE: good alternator, but still no charge
 

do you have a voltmeter? You should see approx 14 volts across the batteryposts right after startup.
Battery terminals clean and tight?
Have you had the battery load tested?
Battery should have 12.5 volts or more with engine off.
Put one meter lead to the alternator battery connection terminal, the other meter lead to the battery post a reading of .2 volt or lessis normal.

RE: good alternator, but still no charge
 

If you don't have a voltmeter go to Walmart and purchase the battery monitor ( ~$15) that plugs into cigarette lighter socket. It monitors voltage as long as keyswitch is ON and will show if correct charging voltage is present, and if battery is declining overnight (battery voltage slips from 12.2 > 11 volts for instance).

A good alternator can still not charge, if it's not turning fast enough. This can be caused by a slipping crankshaft drive pulley w/ the harmonic balancer rubber sandwich worn and slipping. It's happened to me, and heard of it from others. Less likley but possible.

good luck

RE: good alternator, but still no charge
 

I have a voltmeter, I tested the battery while the car was running (ground and positive terminal). That read about 13 volts. Then I tested the alternator and a ground, and it only read 12 volts. So does this meant that there's a leak in the wiring harness?
One thing that kind of blew me away was one night I went to unplug it while it was still running, for some odd reason i decided to rev-up the engine with the throttle cable, and I noticed that the alternator was sparking (maybe trying to get a clear ground). I just don't understand it, and hate to play around with it a ton because the way Honda designed the position of this alternator, its a pain in the butt to get out. Its behind and under the engine and the axel needs to be out in order to have a clear spot to take it out. UGH.
Thanks a ton for your suggestions.

RE: good alternator, but still no charge
 

Some sparks are normal where the carbon brushes contact the rotor. If these were external to the alternator body, something is wrong.

It's unlikley to have 12V on alternator and 13V on battery, at same time IMO. A battery monitor may help clarify whether alternator is performing correctly. Honda's have a load detector which unloads the alternator at times to save energy, however battery voltage should drop no lower than 12.2-12.5 volts during this brief unloading. I know they had load detector circuit in 90 Accords, but don't know about 89 Accord.

You could have something unusual such as damaged crankshaft pulley described above. Full time monitoring will show what's happening. You can make your own w/ a cigarette lighter adapter tied to your voltmeter (digital?).

good luck