Alternator died and when I replaced it, the truck is skipping and backfiring
 

Good morning,
My H2 started running funny, making no power and not liking to shift. At that point I realized the alternator was bad and we towed it home and I replaced the alternator.
I replaced it last weekend, fully charged the battery and was finally able to take it for a ride this morning. It's not making the amount of power it should, and it has a little intermittent skip in it. Should this go away if I drive it a little bit, or where should I start looking?
And I really appreciate the help I get from you people.

This doesn’t seem like an alternator issue to me. Once the alternator is replaced it should be good to go right away.
did you get a check engine light?

No CEL, was wondering if the ECU may have learned some wrong stuff from the under voltage.
THe sensors work in an assumption of 12-14 volts. If that's off, they can give lots of bad info. Was hoping....

WTF?: "making no power and not liking to shift"? https://cimg9.ibsrv.net/gimg/www.hum...fb7946d9e5.gif
Question: "where should I start looking"?
Answer:
Reinstall old alternator and drive to your local repair shop for a proper diagnosis/repair. https://cimg6.ibsrv.net/gimg/www.hum...c5ca4734ad.gif

Ok.....
Since the vehicle makes 3.2 volts DC with the old alternator I will get right on that. It makes 14 with the new one.
Thank you for the brilliant advice.

3.2v? Yet you never seen:
https://cimg8.ibsrv.net/gimg/www.hum...64377a43e6.jpg

https://cimg4.ibsrv.net/gimg/www.hum...96a4bd5e03.jpg

Yep
 

That is exactly what it did when the alternator quit. It started running really lousy at about the same time.
I've seen some Dodges from that generation that would pretty much lose their minds from the undervoltage. You would have to run them a couple hundred miles with things being weird until they would straighten out.

It's kind of amazing, I have to use twice the foot I used to to get up a hill, and I'm not getting a check engine light.

Get a quality scanner that can access all modules! In the meantime check here:

Thank you very much. Up until a couple years ago I was a partner in a garage not too far from where I lived so I never bought a good scanner. I have the homeowner version but I don't know if that will do this.
I will get a watch on that as soon as things are settled here, watching little monsters now.