Okay, so I need help and have run out of options, besides taking the bike to the shop. Which I don't want to do.

Bike is a 2003 FXSTDI

Background: Wife and I started a business and got pregnant within a year. So the bike sat for almost 3 years. I was terrible and didn't put it on a charger or drain the gas. So got new gas and battery, cleaned the injectors. Started it up, ran like **** - tune gone? Got the bike tuned and running good.
On the way to get the tune, my speedometer went out. It would freeze on what speed I was going and no display of the miles. Randomly come back for a few minutes to freeze again. Turn signals won't auto cancel also. Found if I take ignition switch out and bang in it, the speedometer would start working for a very short period of time.

Check ALL wires - Good
Change ignition switch - same issue

Read on some online forums, that the speed sensor being dirty or bad could cause this exact issue.

Removed it and cleaned it - same issue
Replaced speed sensor - same issue

I have tripled checked the ground wires 10 times! With my power vision connected, I can read RPMs but not speed on the power vision itself. So I don't believe it has anything to actually do with the speedometer itself or the wires under the tank (I checked the wires anyway). I'm starting to think ECM but that is expensive and don't want to pay Harley's steep prices to diagnose my bike right now.

Any ideas??

 

Well, it sounds like you covered every base that I can think of. Based on what you did I assume you removed the dash and could see the back of the speedometer. This may should stupid, but did you look for mud dauber nests? You'd be suprised at the problems they can cause, especially with ignition components and plug wires..

 

When my 2000 did this I found my voltage regulator was bad . It was putting out like 19 volts
At idle!

 

Yes I checked for any kind of signs of bug/mice... No signs... I checked behind the dash and found no loose/dirty connections. Clean Everything anyways...

I did check voltage regulator. 12 volts while bike was off... And 14 volts while idling and giving it a bit of gas....

 

If it's at 12 volts then your battery is weak.
Battery at full charge is at 13 volts.

 

What were the storage conditions?
Being exposed to dampness over 3 years could create problems with electrical.
The factory speedometer is electro-mechanical.
The little electrical gizmo that turns needle could be stuck

 

Get an aftermarket speed switch. The Harley ones have been known to be DOA brand new.

 

If when its frozen and you cycle ignition does the needle do its full arc sweep and come back a little lower than before. Not sure on Harleys but most speedos have a stepper motor that reads the speed signal and reflects on speedo. This could also cause your turn signal cancellation issue.