'71 Bonne 455. Fan works intermittantly. Turn switch to "on" fan blows. Crank engine, no fan at any speed. Turn engine off, turn switch back on, no fan. Turn on, fan blows at every speed, crank engine, no fan. No pattern, just intermittant. Have unplugged, re-plugged both relays and blower resistor to check for bad connection. Fuse, of course, is ok. Bad relay, or what? BTW, has custom air, not auto temp. Blower motor sounds fine at any speed when working. Heat, vent, or AC makes no diffrerence. Help!