Have you verified there is power at the receptacle?
It could one of many things:
1. No power at receptacle
2. No power going through the cord.
3. No power going thru where cord attaches to RV
4. No power going to the transfer switch(assuming you have an ATS).
5. No power coming out of ATS to power distribution center
6. No power in distribution center
7. Breaker tripped at receptacle
8. Breaker tripped in power distribution center.
Either you or have someone who is handy with a volt-meter start checking at the receptacle and follow above path, to see how far the electricity is or is NOT getting.
