alternator bouncing back & forth makes lights flicker ?

[high output]

My gage is going up & down with the motor makes lights go dim & bright right along with it , would that be voltage regulator taking a crap ?

[erics diesel]

sounds like it could be but also check the big wire on the back of the alternator for corrosion

[85_305]

Does it do it on startup? Sounds like the initial GP draw on startup.

[high output]

Originally Posted by 85_305

Does it do it on startup? Sounds like the initial GP draw on startup.

No it does it driving at full speed....

[85_305]

Right... after a cold-start? Will still flicker while driving if the GPR is on.

[high output]

it dont flicker it goes in & out all day & all night long my lights go bright then dim all night not right after start , my budy says my alternator is going out..

[01powestroke]

my dads truck did the same thing when the alternator went out

[85_305]

In that case yes it sounds like alternator. Stick a multi meter up to the output on the alternator and see what it reads when all of this happens.