Fuzzy,
Box issues?
Generator issues?
Lift Gate issues?
Dolly issues?
All of these have to do with the dealer and vendor who did the work, not freightliner. The air problem can be something simple or something that has to do with the installation of the stuff on the chassis. So your beef seems to be with only the dealer who I think should have stepped in.
But anywho ... I would start with the most serious issue - the engine. I would take it to Cummins HAVE THEM document the issues, GET AN ECM DUMP on paper, and get the repair paper work in order but see if they can fix it regardless.
In the mean time, I would go to the lender and talk to them, lay it out with documents that you already have. See if they can get something moving on the dealer's part - most likely they worked with the dealer to make these loans, many get referrals from dealers. THEY have a vested interest to see that truck fixed, if they act they don't - then talk to them about taking the truck back and let them deal with it.
WHATEVER YOU DO DO NOT STOP PAYING THE NOTE ON THE TRUCK!
I would also talk to the regional rep for Freightliner to see what can be done with the dealer. Call customer service, AND send them an email at the same time. If they don't help you, go right to Daimler corp.
Take each issue separately and document them separately. I would contact the makers of each item to see if they can support their warranty, if they won't - it is time to bring it to the dealer. Most of the time they will back their product.
Now without these things being done, your chance of a lawyer winning under any "lemon laws" are going to be slim or even to totally resolve the issues. You have to do more than go to the dealer.
The thing about this business is that you and others need to get it together when it comes to tools. Sorry to sound harsh but I have been saying this for a few years now and a lot of people will poo poo what I say as a worthless way to waste money. I mean it is odd that a few of us who know what to do to protect ourselves keep saying you need the right tools that protect you before you venture off in this business. It is not the money that matters as much as it is to protect yourself.
This just proved what I have said to be right - get a lawyer and an accountant before you get into this business and work with them, build a relationship with them. So what if the cost is a few hundred for retaining and advice, they will pay for themselves in situation like this when you need a professional to step in.
THe OOIDA, with all their great work is not interested in your business or your problems, they are a group that helps everyone. It is good for those who don't want to spend the money and expect good things to happen all the time.
I stress all of this because each person doing this work does it for different reasons. Each has different goals and different needs, so having someone to understand what you are doing, knows you and how you are doing things and builds a trust relationship with you can step in and advice you before problems become problems or at times like this. A lawyer could have talk to the dealer for you the second time it was in the shop or guide you to the next step instead of trying to find answers on your own and risking more losses.