Are you planning on working permanently or traveling and working? There would be different types of jobs for each.
Since you're a certified mechanic I would recommend you check the RV facilities. You might have to train for RV mechanic though. We have friends who work for the forest service during fire season. You have to be ready to go when called. For your wife, perhaps a RV park office.
There are more and more young full-time RVers nowadays and they need to work so there are things out there. Many are able to work from their RV via internet. Try Googling 'RVing and Working' or something like that. You might come up with some blogs of working RVers to read. Of course, there are always volunteer jobs in campground and normally you'll get a campsite which can save you some money. You might want to post something on the Full-timing Forum. Good luck!