Today I fired my 73 Scamp up for the first time this year, & was instantly reminded of a problem it had last year, the needle on the factory amp gauge jumps around, not a ton but it's noticeable, my Autometer Tach also dances around a bit, anyway last year I replaced the battery, the voltage regulator & had the alternator looked at, (they checked it & replaced both field brushes) problem persists, so today just for kicks I unplugged the top-most field wire from the alternator, alt gauge & tach stopped jumping, although understandably reads a slight discharge. So do you guys think it's the alternator, voltage reg. or a wire issue?

 

in addition, the brushes might be a bit gritty from sitting.

 

thanks for the input guys, I was bored yesterday, so I replaced the wires from both field contacts, up to the first plastic connector on the harness, this cured the problem. So I guess the 36 year old wiring harness is at the end of it's service life. Does anybody make a GOOD harness(Bulkhead connector forward) for 73 A-bodies?