Alternators dying after new HU install?

So, I recently installed a new stereo HU in my wife’s ‘05 Tundra. The alternator died shortly after, and I just replaced it. Now it is dying again. The alternator is 130 amp. The new stereo has a built in amp rated at 4x55w of power. Would leaving the factor amp connected be causing the issue?
I am very much a novice when it comes to these things, but I checked all the wire connections, and they look good.

 

New or rebuilt parts can be bad right out of the box. You can verify the current the alternator is putting out to see if it is bad and I would also test your battery, it could be bad or have a deal cell.

 

Alternators fail, not uncommon with age. What you are describing sounds more like a battery that would be failing.
Did you have the old alternator tested? The replacement could be bad luck. Have you had it tested?

 

I haven’t had the new alternator tested yet, but the battery is less than a week old. I figured I’d change them both at the same time.

 

Also, the truck ran perfectly with the new alternator for 3 days before I reinstalled the stereo.

 

Where'd you get the new alternator? Stick with Denso reman. We had another member get one from the local auto parts store and it was bad also.

 

You need to retrace every last little item you touched. Then look adjacent and make sure you didn't bump something.

And the belt. You've mentioned you're a newbie/novice. How do you know the alternator belt is tensioned correctly? Push perpendicular on the alternator belt with just moderate force of a single finger. Then report back how far that belt is deflecting.

 

Ok, I’ll check that.

 

I got the alt from oreillys.

 

Just checked the tension. It moves, but very little. Maybe a 1/4” of room