Greg. Please check the wiring very carefully. I just fried my wfco and a bose stereo because of a wiring error jsut yesterday. I have a 72 tradewind and it is a 3 prong 30 amp plug for 120 volt.
I had "help" wiring a 30 amp cable to convert a 4 way 120/240 into a 3 way plug. this was intended to be a 120-30a circuit. (I know..there is a possibility that there could be slight NEMA code violation doing that

). The long and the short ..no pun intended.. is that my friend inadvertantly sent two hots into the system. Many 3 way plugs are Hot-Return-Ground and are 120 volt. Be very sure you have a 240 system if you are planning on sending 240 into it. Get your meter out and check the hot to haot side and see if it is actually 240. I had the meter but didn't check before the system was plugged in.
My damage was not too bad. The wfco (great chargers!) and the bose stereo were the only casualties. It sucks but I had a meter and should have checked the work befor it was plugged in.
When the AC fan ran as hard as it did I figured it out real quick, but not quick enough. I don't want to see someone with a 70s series trailer get a 240 shot through a 120 system

like I did.
Now I will be ordering a new wfco as I seriiously doubt that the warrenty covers running a 240 v shot into it. The stereo will have to wait.
Better that I feel a bit foolish but pass it on than have another make a similar mistake...use your meter!