Norcold no 12V, no cold

On the back of the refer there should be a NoCold recall black box. Normally when you do not have any 12V power to the refer, the red light on it is lit... supposedly because of a overheat problem BUT they are on revision F of this POS. This black box has four wires... two small to the heat sensor in the flue and two large for the 12V power. Pretty sure it's a blue wire from it to the 12V input on the control board. Check that you have 12V on the other large wire (mines yellow) and if so, then on the blue wire. If you have power into the POS but none on the blue wire and you do not smell any ammonia or yellow stains around the flue, bypass the POS by moving the yellow wire to where the blue wire is connected to the control board. You should now have power restored and it should start cooling again BUT you need to keep an eye on flue area as there is a slight possibility the POS actually worked. If you have power on the blue wire then you need to do what OLd Biscuit suggested above.
If you do not have atleast 11.8 V on the yellow wire and blue wire, then the refer is not going to work and you need to charge your batteries.