The dash light actually serves two purposes. First is excitation, just as you explained. The second is to alert you if alternator output drops below battery voltage -- the alternator is failing to produce charging voltage. Not only the DeLorean is wired this way -- it's pretty common on most cars (at least circa 1980's). You should always glance for the "ALT" or "CHG" light to come on when the vehicle is first energized. Bill Robertson #5939 >--- In dmcnews@xxxxxxxxxxxxxxx, "Tell you if you ask." <racuti1@...> wrote: > > It's not a "command signal" in the manner you imply. An alternator > requires an electrical current through the copper windings before it > will begin to output electricity. For instance, you couldn't just spin > the altnerator by hand to charge a dead battery. The windings need to > have a current passed through them first. The dummy light acts as a > resistive load that accomplishes that. > > You could just as easily install a small resistor in place of the dummy > light to achieve the same effect of "starting" the alternator. Speaking > of which, I know a lot of people have been replacing all of their dash, > door and marker lights with LED's. If you replace the alternator dummy > light with an LED, you'll need to install a resistor in-line with the > LED because an LED is not enough of a resistive load to charge the > alternator windings. > > I'm sure that this has been covered in the archives. > > Rich A. > #5335 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/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: mailto:dmcnews-digest@xxxxxxxxxxxxxxx mailto:dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> 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/