After scouring the internet and HDForums, I still am at a loss as to what is wrong with my combination speedo/tach. I have a 2009 Crossbones that I installed the Harley combination speedometer tachometer in, about 1 1/2 years ago. It has always worked and have had no problems with it. Last weekend I went out to the garage to do some work on the bike and noticed that every indicator light on the speedo was lit up like a christmas tree (PHOTO #1), even though the power switch on the dash was in the off position. When I turned the power switch on, some of them went out, while others just dimmed (PHOTO #2). I immediately thought that maybe some water had gotten into the speedometer and it was shorting something out internally. I pulled the speedometer, brought it into the house, did my best to dry it out overnight and reinstalled it the next day. When I reinstalled it, with the power switch in both the off and on positions, the red security light and the battery lights come on, and in the display area, different characters light up and keep changing, almost like my speedometer is on crack or something. Its not showing codes or anything like that, just individual lines lighting up and turning off continuously. I plugged in my stock speedometer (PHOTOS 3 & 4) and it looks like it is working ok, although it doesn't have near the capabilities of the speedo/tach combo. I went to the local dealership, and of course they told me to bring it in, which I'm not really wanting too. One of their guys suggested my battery might be low and it could be making the speedometer act funny. I keep the battery on a tender and measured the voltage today at 13.1 volts. Another thing they said was if I had anything plugged into the diagnostic port under the seat. At the same time I changed the speedometer, I also did a 107" engine upgrade and added the Thundermax computer. This computer uses the diagnostic plug so, yes there is something plugged into it, but it's been plugged into it since I've had this speedometer.

I'm pretty much at a loss as to what to check / do next. Anyone have any ideas?

 

This is a video of the speedometer of when I say its acting like its on crack.

 

That is wild, have you tried to unplug The thundermax?

 

I haven't tried unplugging the thundermax. What are you thinking? Unplug it and then plug it in and reinstall the map? Basically what you do when you first install the thundermax?

 

Well I would be curious to see what it does, that would be the first thing HD would do.
These bikes are more of a computer than mechanical now days, we all know how PC don't like anything Mac:-)
Sometimes we need to just reboot.

 

I see your point, and it sure as hell can't mess anything else up right now. I will give it a try tomorrow and see what happens.

 

So I had a chance today to work on the bike. I completely unplugged the Thundermax and went through per its instruction sheet and hooked it back up, remapped it and still the speedometer doesnt work. I've also double checked the plug, wires and pins going into the plug and everything is good. I think I might just have to bite the bullet and 1) take it to harley or 2) get a new speedometer.

 

Hope the dealer can help. Had problems with combo on my street bob. Said it was my fuel pak. Uninstalled and same issues. Reinstalled stock speedo and fuel pak. No issues.

 

That sucks big time, it is such a nice speedometer. Sorry I don't have any more advice, these modern electrical parts are not like our old toasters, that we just tear into them.

 

That's the same speedo/tach I've been looking at. I hope this combo doesn't have problems and the problem is on your end. Keep us posted on what you find.