1997 Chevy K3500 Dump with plow- What alternator output needed for dua

[jpgalich]

Hey, hoping someone can give me some good advice here. This is my first time posting here so hope I'm in the right area.
I've got a 97 Chevy K3500, 5.7l, auto trans. It's got a big plow on it and 8' dump bed.
My alternator just burned out on it. It's got a dual battery setup to handle the electric hydraulic pumps for the plow and dump bed piston.
I bought the truck like this and I'm assuming that the alternator should be a high output unit, not sure what's in it now.
Want to know what I should install in here that would best suit this setup?
Also, it looks like whoever set the dual batteries up just kind of threw it together. What's the best way of setting these up to get the most out of them? I've seen people talk about using an isolator to keep the auxiliary battery from draining down the start battery, but wasn't sure if doing that would work out with this or not
Appreciate any input
Thanks

[Duelin]

The amperage output should be stamped into the case. If it worked ok with that alternator I would replace it with the same thing. In my case if an alternator or starter that has been working without any problems I take them to the automotive electrical shop and have them rebuilt. I have found I have less problems doing that rather than buying a different unit.

[jpgalich]

Well, I gave the VIN to a GM parts dealer and apparently the replacement stock alternator for this truck is 100amp.

Actually everything does dim out pretty good when I'm using the plow which makes me think that the alternator isn't keeping up with demand.