I have a 1998 EX that recently started having problems with the headlights dimming intermittently.This would happen at any rpm. At the same time the battery light would come on the dash.I pulled thealtenator and had it tested, which showed what seemed like a bad diode. I replaced the altenator and it seemed to work well for a couple of days and now it is back but not as bad. The battery light does not come on but the lights still dim slightly.On the AllDATA websiteit showed a TSB #98-029 for Headlight/Dash Light - Intermittent Intensity Changes.Their procedurecalls for first checking the battery voltage which should be at least 13.0 V, mine wasat 11.1 V.The enigne has been cranking slow and it was an old battery so I replaced it. The new fully charged battery is at 13.2 V. Now I run the engine and the charging voltage off the altenator at the B connector still fluctuates between 12.8 to 14.6 V?ALLDATA's Probable cause is a faulty voltage regulator? So that means that the new altenator that I have already has a bad regulator??I have checked all of the connections that are in the charging circuit and all are clean and tight. Short of taking the altenator off and having it rechecked, I don't know where else to look. I was hoping someone may have had this problem andfound the solution???

Thanks

 

If your alternator belt isn't loose or slipping, then you likely have to replace the alternator. Was the replacement alternator rebuilt or new? Isn't the replacement alternator still under warranty?

 

The altenator is a rebuilt from Advanced Auto, still under warranty, that's why I'm leaning toward taking it back. But, I figured that I would see if anyone had any other thought first. The belt is in good shape and doesn't appear to be slipping.

 

Return the alternator as soon as possible. The information provided in your thread definitely warrants the return. When I had a similar problem, AutoZone replaced my alternator without any hesitation.

 

FYI,

I took the altenator back to Advanced Auto and they tested it and found the output at 12.6 V. They tried another one and it tested at 14.5 V. They exchanged them with no problems. I put the new one on and the charging system is nowsteady at14.5 V. Perfect!

 

Nice to hear you had a good outcome.