Check the tension of the alternator drive belt. Other than that you might have an alternator bearing problem, though that usually dosen't cause a charging problem until it gets really bad. Stranger things have happened... You could also have a wiring problem between the alternator and the battery. The power from the alternator is not reaching the battery, causing the alternator to put out its max output to try to bring the voltage up, this loads the drive belt more and makes it slip. Also you could have a failing battery, not likely though. You should get a voltmeter and fashion some long leads (I use these great retractable leads that are 10' long and wind back into a spool for easy tangle-free storage). First check your battery voltage across the battery terminals while driving. Should be 13.5-14.5ish all the time. Now hook one lead to the main output of the alternator and one to the positive battery terminal (using those long leads) and drive again, if you measure more than 0.5v you have a problem. Now do the same between the alternator case and the negative battery terminal. Again, more than 0.5v is a red flag. If the battery voltage is really low and there is no drop in the cables, and the small wires on the alt are correct, you have an alternator problem. I would check the belt tension first. Also try turning on the high beams and the blower, and the A/C. Really load the system to see if you can get the problem to duplicate in your driveway. Hope this helps, Matt Smith --- In dmcnews@xxxxxxxxxxxxxxx, "usndmc" <usndmc@xxxx> wrote: > A little over a month ago I replaced my original 90-amp Motorola > with a D150 from John Hervey > Everything was working great the last month, until about 5 days ago To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/