You could have a stuck closed check valve on the output of the hot water tank. In order for water to come from the hot water tank, that check valve must be open.
However, you are not getting any hot water from any hot faucet in the rig, but you are getting a full flow of cold water only.
If you have a thermometer, measure the temperature of the cold water coming from a cold tap. Measure the temperature of the hot water coming from the hot tap. If there is a difference, you are getting some hot water mixed.
Measure the amount of volume from the cold tap, and the hot tap in a measured amount of time. This might tell you about a restriction in the hot flow. If you find they are not the same but much different, perhaps you have a partially stuck shut check valve on the output of your HWT.