I see there exists a good number of cases of the neutral light coming on in 5th gear. I too am experiencing this on my 2005 Dyna. It appears to have started immediately after I changed over the transmission top cover to a chrome one. There must be a physical difference in between covers and ask if anybody out there has sussed it out as to what it may be.
Has anyone had luck shimming or using alternative neutral switches?.
Does the switch need more depth of perhaps less protrusion into cover??
I've got my original transmission top cover but not yet inclined to put it back on...hoping there is a quick fix someone may have??
Funny enough even the transmission cover part numbers stamped inside are the same between the chromed and non chromed original I took off.

Thx

 

What year and model of bike? What part number cover did you order? The number stamped on the inside is a casting number.

 

Part number of both my original removed is 34471-99b and same as the chromed one now fitted.
Jim

 

Take the sending unit out clean and lube the ball before you replace it. Simple to do.

 

I rode the bike to a halt in 5th with the neutral light on. I then slowly in 1/4 turns eased out the switch and re-powered to a point where the ball protrusion lessened and the light extinguished....less than finger tight t this point..Unfortunately this also took away my neutral light once in the 'neutral' gear select...so I can see a common between 5th and actual neutral in so far as switch ball depth.
I fully removed neutral switch and shimmed it slightly and repeated the process however I was unable to get neutral light at all. I subsequently removed the temporary shim and reinstalled the switch and tightened just enough to activate neutral light. I now have neutral light in neutral mode, and when I shift up to 5th, the neutral light gives a quick flicker but then stays off...better than before where it stayed on in 5th all the time.
So, obviously, either a sensitive switch or misrig.
I will get another neutral switch and repeat to see what I get.
I would have leaned to a faulty neutral switch, however, having read the forum that many othershave experienced this same issue upon changing over transmission top covers., makes meet wonder..

Jim