So the other day I unhooked my battery to do some wiring and when I did the needle on the speedometer jumped up to about 3 mph and has stayed there ever since and wont go back to zero or a little before where it should be. I can unhook the battery and make the needle go to the correct position but as soon as I hook the battery back up it goes right back to 3 mph. This causes the speedo to be off by at least 5 mph when I'm riding and was just wondering if anyone else has had this problem. I've tried looking everywhere and haven't seen anyone having the same problem so if anyone has had this problem and knows a solution I would really appreciate it. Thanks in advance.

 

Does this happen with the ignition switch off?

When disconnecting battery, neg side should be first to be disconnected. But for testing purposes, will this condition occur when you alternately lift then reattach either battery post?

 

Yes all of this happens when I have the ignition switch off. When I turn the ignition switch on for the first time if its sat for a while it will go to zero or a little below, but then it will just jump right back up to 3 mph. And yes the first time I did disconnect the negative side on the battery terminal and then also hooked the negative back up last after I got all of the wiring done. And ya unfortunately last night I tried to see if I could hook the negative up first and then the positive but the problem still persists and the needle jumps right back up to 3 mph. I added a fairing onto the bike and added a 10 gauge power wire to the battery along with an 18 gauge power wire for the radio. Then one 18 gauge wire to the negative side of the battery. For the remote turn on I tapped into the orange and white wire under the seat for the ignition of the radio and the amp. The speedometer used to be spot on until I unhooked the battery the first time and now its not even close to where it was. Any help or suggestions would be greatly appreciated, I have no idea where to go from here.

 

I find this often working on the factory gauges. Needles off. allways thought it as just a defect from the factory that the needle was never installed correctly to begin with.

Yes all the speedo's and Tach's both move the needle down and then back up and it is supposed to stop at zero. There is a couple small brass inserts inserted in the needle that I presume somehow is used to locate the needle to zero, but I don't see any kind of pick up inside the gauge used to pick them up.

Maybe there is some way to reset it, but I do not know how myself.

 

May be time for the new HD Speedo/Tach to replace it.
Price not too bad, at the dealer or online.
Sorry about the needle there Bud.
In the future when you can, just pull the main fuse, might avoid...

 

Have you driven the machine yet to see if the needle goes back to zero after the speedo has actually had pulses going into it or just repeatedly turned the power on and off?

 

Ya unfortunately I have rode it for about 60 miles or so and when I'm just stopped at a stoplight or anything it still says I'm going 3 mph.

 

What electronics have u added in the new faring? U said a radio, what else? How did u route the new power wires to get them to the faring from the battery? Does it still do it with the radio unplugged from pwr source?

I ask these questions because i suspect the possibility of inductive coupling between speedometer data/pwr cables and either your new electronics or new power feeds to the new electronics or both.

 

I added a kenwood radio, rockford fosgate amp, and then a 12 volt outlet. For the wiring I pulled the gas tank and then ran the wires under the tank with the rest of the wires, then I have them going through that rubber casing with the rest of the wires, then running up into the headlight area under the handle bars and then coming up through the small hole that the wiring for the hand controls come up through and then into the fairing. And I just went out and tried it without having any of the added wires hooked up and it still does the same problem unfortunately.

 

Try running the diagnostics on it. The needle on the gauges will sweep the whole range and should return to zero.