2004 125 GT. When I turn lights on, the tach doesn't work and the fuel gauge rises. What's wrong?

SOURCE: my rev counter, speedo, fuel gauge and temp gauge

try to check yor meter conection at the rear of your meter.there is a loose connection due to vibration

SOURCE: cbr 125 rw 7 instrument panel

Sounds like you have a ground fault. I once had a car with a faulty ground wire on the headlight, when I put high beam on the speedo would jump to 170km/h and the indicators would glow dimly. Sure sounds like a similar ground fault to me, check all the ground straps, from the headlight or anywhere else you can think of.

SOURCE: i have a 1999 yamaha dt 125 r and the light bulb

Hi fit butcher,

The assembly of DT's speedo are all the same after 1998 models. below is a picture of a 2002 DT125/175. the assembly is the same, only that yours does not have a tachometer, yet the placement of the assembly is the same.



and here is the manual for your unit,

hope this helps,

regards,

voodoo

SOURCE: have no electrical system at all. lights horn fuel

G'day, sounds like maybe you've blown your main or ignition fuse, would be the first place i'd check, then maybe battery conections to make sure the wiring looms being suplied with power from the battery. Hope this helps :)

SOURCE: yamaha xt 125 07 no speedo or rev counter any

This is a very common problem for the yamaha xt 125. I suggest that you either buy a new Heads up display or you take it down to yamaha and get them to fit another one, which i think might be free of charge due to it being a problem with the bikes.