Series 3 lights

[ep7360]

My series 3's headlights and gauge lights cycle from bright to dim around every 10-15 seconds. Is the alternator about to give up the ghost?

[4flattires]

Got a voltmeter?

Its always easier with a quick check of the facts (volts).

1. Check voltage across the pos and neg batt terminals.

If large voltage surges occur, my first guess would be voltage regulator.

Jeff

[ep7360]

Mystery solved! Bad alternator. As I was driving home from work my lights started to go through the normal bright and dim routine when all of a sudden my headlights just went totally black. It was 11:00pm and I was 40 miles from home. So by the grace of God and weak parking lights, I made it home with out getting a ticket or running off the road.
My internal voltage regulator went south and fried all my external light bulbs by the time I got home. After replacing the alternator and bulbs, all is well.