voltage drops

Hello, I have a Jeep Wagoneer with a stock 63 amp alternator. I have a 4 gauge wire going from my battery to my amps. I use to run a smaller system with the same wiring. Now I run a larger system with the same wiring as before. The "new to me system" is one that came out of my friend's car. He used the same amp wiring kit I have in my Jeep without issue for years. Now the for the problem. With the stereo on or off, my voltage will be at 14v for 5 seconds and then drop down to 12v for 2 seconds. Then back up to 14v and repeat. When I disconnect the amps from my battery the problem goes away. Do I need an alternator that puts out more amps? Maybe a short? What do you all think? Thanks, Forrest

63A? How much current does your "new to you" amp draw?Kevin Pierson

Does the amp play?

A 63 amp alternator won't cut it with any amp that has a 30AMP or more fuse in it. 20Amps is even pushing it for that low output alternator. I would upgrade that alternator if you plan on anything at 1000 watts. Also? I see a lot of people wanting help, but never post the type of equipment they're using; no brands or model numbers. It's almost impossible to make any kind of assessment without that information. Everyone has to guess, and that's no help.

That the "voltage will be at 14v for 5 seconds and then drop down to 12v for 2 seconds. Then back up to 14v and repeat" suggests bad charging, though I'd expect only old external electro-mag regulators to bounce like that. But internal electronic regulated alternators can still have intermittents or worn brushes. Just in case it is faulty or you are thinking of a larger alternator anyway...