weird voltage problem

[talon_frost]

ok so the past couple weeks my volt gauge was reading normal, them all of a sudden its goes from 14v to 16v and sometimes even 12v to 18v up and down up and down up and down , i have a new altinator installed but when I got it the dude told me the wheel on it was alittle smaller could that be the problem? also some other symptoms are the lights flicker ''ALL OF THEM'' and my idle sounds funny.... kinda like its surging but it goes with the power issue if that makes sence?anyone know whats going on maybe a ground?? also would like to add that i relocated my battery to the trunk but the gounds on the battery are perfect to the body of that car..

 

[steve]

Bad alternator. The voltage regulator is shot and little excursions to 16 and 18 volts are going to ruin your battery and may blow out the lights, radio, and ECU.

 

[talon_frost]

but the altinator is brand new?

 

[luv2rallye]

but the altinator is brand new?

ha, ha...how many hundreds of times have we heard that on here?
Alternator quality at auto stores: http://www.dsmtuners.com/forums/newbie-forum/263621-alternator-output-problems.html#post151468330

 

[KelTsi90]

Also check the grounds.

 

[eder-loco]

Yep, check for grounds. My did that when my Negative terminal was loose.
But i have also gone thru 4 alternators anyways. they all suck.
get a saturn alternator.

 

[steve]

It goes without saying that he should check the grounds, well really all the wiring, including the sense line from pin 1 of the alternator connector. The most common cause is a bad alternator and as pointed out being new actually increases the odds of it being bad not lowers them.

With the battery being relocated the chance of wiring errors/bad connections goes up but bad alt still ranks higher.