My speedometer now jumps all over the place whether I am moving or not, Would I be right to assume I need a new speed sensor? Or would a low battery cause this? It is over three years old and sometimes flashes if I run all my lights at idle.
Thanks

 

700atwashington, sounds like the speed sensor. as far as the lights it could be a couple of things:
1 do all the lights and speedo flash? and does it take a couple of minutes for it to start doing it?
2 do they work ok above idle or still the same?

 

Check all your grounds and connections.

 

None of the lights flash, I just get the battery signal flashing sometimes when I first start it up, if I rev it up it usually goes away.