on my 08 suzuki king quad 450 4x4 the battery went dead because my son left the headlights on. since then it had been working fine but you had to pull start it. then last weekend i took it out hunting after about a half an hour the display went dead but atv was still running then noticed fan hadnt kicked on in a while i bounced the front end pretty hard and got the display to kick on for a little at that time the fan also kicked on. then a minuete later they both kicked off. then i got them to come back on the display showed that the fuel injection system needed to be looked at. i was wondering if i replaced the battery if that should fix the other issues or if i will have to work on the fuel injection system as well.

 

you mite wana start by testing your battery, see how many vorts it has. but it kinda sounds like youve gota short somewhere. look at a wireing diagram and see if your fan and display are anywhere on the same circit. when you say your shakeing your atv that really sounds like a loose connection or short.

hopefully the suzuki gurus will chime in with more specifics
good luck!