2015 Tripac Evolution alternator swap

I've got a 2015 Tpac Evolution Arctic package, 120 amp alternator. About 3k hours and I I'm getting all sorts of codes including alternator codes. I have checked all fuses and replaced the big 50 amp top fuse that fails on the back wall of the main unit.

Here's the question, there are some reputable 65 amp alternators online for around $100. Thermo King wants $400 for the replacement 120 amp. Can I put a 65 on it? I know the older Tpacs had a 65 so I'm pretty sure it's physically the same. I understand it will put out a lot less power. I'm happy starting the truck when I need more juice for microwave, etc.

I'm also wondering what 'single voltage' vs. 'dual voltage means on some of the alternators and voltage regulators I'm seeing online. Anyone know?

 

Thanks, I have no idea if that's what they mean. Some of the voltage regulators and alternators on sites like Thermo-by-Products are single or dual voltage. I called and the guy there today couldn't answer, said he'd have someone that knows call me back.

 

Yes, I'm familiar with the sense wire and I knew what you meant. I've cleaned both connections at battery (big fuse and sense wire fuse and terminals) and also checked every other fuse. No problems there.

Yes, I've checked them too. I've pulled all grounds and cleaned them. Pulled all the wires off the alternator as well (power and ground).

I also added a fresh ground to the board inside the cab. This was on the recommendation of a Thermo-King tech awhile back. He said the boards sometimes lose ground but there is a big ground lug on the board. You can just run a fresh ground to body from that lug, which I did also. Everything on the board checks out but I'm basically just checking for power and ground, I don't know any more of the specific voltages or what not to check on the board.