Battery fully charged cables firmly connected turn key sometimes get instrument lights, turn key to start instrument lights go out and will not turn over. Turn headlights on nothing happens.This is in fleetwood motorhome with ford chassis 460 engine. Have been having problems with battery draining as well. key seems a little stiff. have a main dissconnect switch in motor home if I engage switch a few times in a row I can get the instrument lights to come on when key is turned part way ,when turned all the way lights go out starter doesnt engage