ips 600 gear box. will not go into forward

Have you looked at the drive oil, Drive could be full of water and need a rebuild. Solenoid for forward gear could be bad. Call a Volvo dealer as parts swapping is going to cost you a whole lot of money on these.

Do you mean that YOU bought a rebuilt unit and YOU replaced it?
If so, you'll forgive me for highlighting that this is not exactly an easy DIY job, since it involves both mechanic and electronics, with specific competences and also dedicated instruments for both.

And even if I know nothing about your competence and experience, the fact that you are looking for suggestions on a forum makes me guess that you neither are, nor had the job made by, a trained VP engineer.
Which I'm afraid is what you must find and involve, even if that will hurt your wallet for good.

OTOH, if the job was indeed done by an official VP shop, forget all I said, because in this case the solution to your problem is much simpler: just go back to them and start shouting till they'll fix it!

I can't offer any useful advice, but I certainly sympathize with you being "stuck up North" in or above British Columbia with few qualified service points for service and repair. I've been in Campbell River, Vancouver Island, British Columbia, Canada where there is an authorized dealer for a part I needed for the yacht I ran, and still had difficulty getting parts from a major city in another country in a timely fashion. That was a Northern Lights part from Seattle, Washington U.S.A.
A couple of hundred miles as the float plane flies, but one bureaucratic agency (Customs) between us
Here's hoping someone can help you!

I’m confused. You say you had a Certified Tech do the rebuild and install. But then you say it failed on the first run within 200 yards. So does that mean the mechanic never tested the thing? Just did the install and left with no trial?

That was just a half joke, meant to say what Dockmaster just suggested more accurately.