That's right, If the bulb goes, so does the alternator. The voltage going thru the bulb supply's the power for the regulator in the alternator( Exciter Voltage ). I can do away with the problem, but you wouldn't have a battery light any more.( Remember #161 bulb only.) Then you may be ok. Do not run a straight voltage to the regulator. If you do then you will burn it up. John > What's that about making sure the dash light battery bulb? Are you saying if the Dash bulb is gone the alternator isn't > working to full capacity?