I have replaced two 18"fluorescent lights in my RV ceiling. The problem is that they only stay on for approx. 10 minutes then they go out. If I turn them off for 10 min and then back on, it does the same thing. However, If I let them dangle from the ceiling by the wires... the light fixture stays on! What suggestions do you have to help me fix my electrical problem. Thanks for any input you have.