Apparently starter motors can develop a bad spot where they stick. Mine was doing this for about 2 weeks where it would sometimes start right away and sometimes not. I found that doing a quick jumpstart attempt would sometimes nudge the internals of the starter motor just enough that it would start the next attempt. Eventually it decided to stick for good i guess. Replaced the starter motor myself (im no mechanic by any means) and everything has been great since. Ask around on the forums, i got a used starter from a member here for very cheap.

Just my little bit of experience

 

Check the starter relay. Tho that is in the standard diags. Also check the connections in the switch itself

 

And check to ground wire to the engine.. Sounds like its connected just enough to click some and then it finally falls in place enough to start.. Dimming of lights is usually normal until it starts running on it's own.. Shouldn't be battery because it has enough juice to start..

 

Died all together yesterday and wouldnt start at all, so as i am currently stripping my F4 down i thaught i might as well try the starter solinoid to see if its that .... well truth is i forgot i had the spare one until today as well .... just replaced the pack and none of the wires and bingo it started up straight away!!

Cheers for the suggestions.