Time for a new alternator?

[THOR_runner]

So I got a new optima battery for free (long story) so I know it's not a battery issue. When I changed the battery autozone said the alternator was good. That was about 3 weeks ago. Revving makes all the lights get brighter as seen in the video. Can it be time for a new alternator but still check out ok at AZ?

https://vimeo.com/114744490

 

[626 4runner]

With ur engine warmed up put a voltmeter on the battery terminals. Should read at around 13.5v with no accessory lights on. It's funny cuz mine will be 13.7volts at idle but if I open the door and the dome and door lights come on it drops the voltage to 13.5 - 13.6v. The 3.0 slow alternators only put out 60 amps at best on the highway, I believe idle is in the neighborhood of 40amps.

 

[KidVermicious]

Check your grounds.

 

[fourwd1]

Check all the battery cables to be sure they are clean and tight.
There are 3 ground cables, battery to body, body to engine, body to frame. And of course the positive cable.

What is the battery voltage with engine running (using a DVM, not dash gauge)?

 

[RAD4Runner]

All of the above, plus:

1) When we say "CLEAN" contacts we mean bare metal contacting bare metal. Grey metal is not CLEAN electrical contact.

2) Alt output range should be from 13.5 - 15.1V, depending on temp. May fluctuate out of that range momentarily, depending on load, battery charge condition.

3) If you have easy access to headlight fuses, measure voltage there with headlights on. Is should almost be same as voltage at the battery post. If not, you have poor connection somewhere between that and the battery post.

 

[THOR_runner]

Good Stuff. I checked the 4 I know of: batt -> body via fender, batt -> block, body -> head, and I think the last one is batt -> stud on the power steering pump. I didn't have time to clean them to bare metal, but at least they're all connected. The PS wire looked pretty chewed up for some reason, and I'll be replacing that as well. I'll also clean the connections to the alternator. Thank you for the tips.