Tach lights going crazy

[rhino17]

I was riding along at highway speed on my '09 K9 last night and my tach lights would go out and then immediately come back on and ramp back up to where they were supposed to be. They would do this over and over, and if I accelerated hard they would really start flashing quickly. Every once in a while, my speedo would also go to zero, but then come right back to where it was. I know lots of you have had tach/speedo problems, so are my symptoms directly related to a specific problem? I've done lots of reading on here, and it sounds like people have done lots of different things to fix the problem.

 

[KaptinAmerika]

Sounds like a worrying issue somewhere in the circuit.
Start with the tach board. Clean it and put dielectric grade on it and in the connector. If problem persists work your way back.

 

[BigDogBro1]

Most likely a solder joint, wire or connector issue.

 

[rhino17]

Thanks. Is it best to take the gas tank off before attempting to remove the speedo?
I know about the Dakota digital and medallion speedo, but is anyone selling a speedo/tach assembly that is better than stock?

 

[Raywood]

My tach will do all that crazy shit when the battery is going out. Check it to see how many amps you have



Sent from my DROID RAZR using Tapatalk 2

 

[rhino17]

Pulled my battery out and took it to AutoZone and they load tested it and said it was fine. Turns out my battery came from Autozone. It's a "Extreme Magna Power", has 310 cca, and has been in the bike for 2 years. I went ahead and bought a new Duralast Gold, sanded all the eyelets that connect to the battery, but am still getting the same tach symptoms. Just trying the easy stuff first. Also noticed the little rubber piece you push to reset the trip odometer is missing too. That must've fell off about the same time I started having my problems.

 

[kklizzy11]

this sounds similar to a problem I had except mine had engine cutout around 3k rpm. mine turned out to be the key ignition switch, the vibrations must have been shaking the internals apart enough to disrupt the power. to check it just take the wires off and connect them to manually send the power

 

[rhino17]

tach symptoms magically went away

took the bike for a 60 mile ride over the weekend, and after the first 10 miles, my tach started working perfectly! I even dropped the hammer a few times and went down some bumpy roads to see if the tach lights would start acting crazy again, but it worked perfect! Should I still take the tach board out to inspect, or is it possible something re-set itself? All I've done is install that new battery from a discount auto parts store, but my tach still acted crazy until now.