Jim.....Unless someone has done it before, I think it will be a pain to find where they tied that interlock in. I do have schematics to the 2005 model line and they may be of some help because I don't think things changed that much.
If your good at reading electrical schematics you might find what you're looking for. Send me a PM with an email address and I'll send them to you.
It may be as simple as pulling a fuse and deactivating the interlock.
The Source Engineering guys use to be Monaco techs and may be able to help you to.