Hi 
 
I have exactly the same problem - last rode mid December, all ok, tried to start it a few weeks later and nothing - just the oil light coming on when I press the start button.  I too read the Haynes manual and thought it was the relay, so bought another from a breaker and it still does the same thing. 
 
Please could you explain how you fixed yours with a little more detail, so that I can try the same thing? 
 
Thanks 
Rob