What could cause the ammeter guage to jump aroung while engine is running?

I suppose the alternator or regulator could have a bad connection which is causing the charging system to turn off and on. You might try wiggling wires or tapping the regulator to see if it stops, either in a charge state or discharge state.

I suppose the alternator or regulator could have a bad connection which is causing the charging system to turn off and on. You might try wiggling wires or tapping the regulator to see if it stops, either in a charge state or discharge state.

When I first fired my car this year, I had a flashing gen light at idle, and 18 volts a 2000 rpm. I found that with so much new paint, the rad support, and therefore the regulator, were not getting a ground.

Had a loose connection at alternator. Guage still jumps a little but not near as bad.