I heard from Dometic. They said the resistance is supposed to be 88 ohms and I probably have a failing heating element. They recommend I replace it. Since I was able to get it out easily it should go back in the same way, looks like a snap. Hope it solves the problem.
I think you're right on and that the heating element needs to be replaced. A common problem.
Not mentioned above, but a very good way to test heating elements if you're knowledgeable enough of electricity is to "straight wire" the heating element. You do this by taking a short piece of electrical cord with a plug, unplug the refer plug from 110 outlet, remove the two heating element leads from the control board, attach the leads to the electric cord (wrap each connection with electrical tape), and plug in to your 110v outlet. In 8-10 hours your refrigerator (not freezer) compartment should be at least down to freezing. Doing this eliminates any possibility of a control board, thermistor, or 12v