I think if it will run on propane then there is probably not a blockage. The ammonia is boiled either by a small flame (propane) or by an electric element (ac). Check you fuses located in the fuse panel where your breakers are located. I blew the fuse to my fridge once while installing a wind shield dometic sent to me so my unit would run on propane while traveling down the road. My fuse panel had an LED that lit indicating which fuse was open.
Also, sometimes there is only one 20 amp circuit in some TT's. Are your ac outlets working. If no check 20 amp breaker and GCFI reset.
Here is a link to Dometic fridge troubleshooting..