I think Lloyd means taking the negative off the battery so the car is running on the alternator only and not drawing from the battery.
Larry Alster 91 Miata White Knight 92 Miata Silver Bullet 92 Miata Honey B 04 MSM MX-5 Whooosh 06 WRX STi Subie -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Eric Schieb Sent: Sunday, June 26, 2011 3:07 PM To: [email protected] Subject: Re: Checking alternator? Which cable is the "negative cable"? I suspect on a '91 that there is a large positive output wire headed to the battery, a small wire to energize the field in the alternator, and a small wire to run the lamp on the dash. The ground is handled through the frame of the alternator. Alternator manufacturers typically DO NOT recommend disconnecting the large wire while the engine is running. They typically talk about voltage spikes damaging things. Can you put a volt meter on the output wire? If you are getting voltage levels above what the battery was at before starting the car, the alternator is outputting something. However, this is based on experience with alternators of that period and not specific Miata knowledge. Eric Schieb On 6/26/2011 3:52 PM, Lloyd Broussard wrote: > I think my alternator is going out. Will removing the negative cable while > the engine running tell me if it's putting out juice. I know this is really > old school, but it's a quick check. > > The car is a '91 with a Link computer. > > > _______________________________________________ > Miatapower mailing list > [email protected] > http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower _______________________________________________ Miatapower mailing list [email protected] http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower _______________________________________________ Miatapower mailing list [email protected] http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower
