Howdy Jason, this thread may help a lot.
If you have two switches inside for the water heater, you have a SWDEL model. I think they all use the same electric element irregardless of tank size.
It's explained in the link above.
Now my questions are:
1: How do you know the electric element is not working. Have you ever tried JUST turning on the electric element while the water is cold (and not turning on the propane/dsi)
2. Have you ever JUST used the electric element before and it worked? A lot of RV's are shipped without the electric element being connected behind the water heater to a 120 volt AC power source. Sometimes it's as simple as just plugging it into an outlet behind the water heater, if it's not hardwired.
3. The light you are talking about, is it the "red" DSI fault/reset ?
4. Are you plugged into a form of 120 volt AC shore power, which you must be for the electric heating element to work.
5. Are you sure you have TWO switches inside to the water heater and may not be confusing a tank heater for a water heater. Post #4 in the link will show you this?