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toyoti
10-06-2012, 04:04 PM
Hi; The backlight on a 2008 yaris doesnīt come on when the lights are off. any help is appreciated. Thanks
CTScott
10-06-2012, 04:52 PM
Which instrument cluster do you have (speedo only, speedo with tach, MPH, kmh)? The reason I as is that some of the clusters I have experimented with have the backlighting without the headlights and others do not.
toyoti
10-06-2012, 05:54 PM
Hi; It has the tach and km. The backlight came on with lights off. Not anymore
CTScott
10-06-2012, 09:53 PM
Check the 7.5A MET fuse in the fuse panel that is under the bottom of the dashboard on the drivers side.
toyoti
10-06-2012, 10:47 PM
Thanks!! Iīll try that tomorrow morning
toyoti
10-07-2012, 11:43 AM
Tried all 7.5 amp fuses. All 0k, still no light. What else?
CTScott
10-07-2012, 01:33 PM
Tried all 7.5 amp fuses. All 0k, still no light. What else?

The 7.5A MET fuse should be the one driving that, but also check the 10A GAUGE fuse and 10A ECU-IG,
toyoti
10-07-2012, 07:38 PM
Hi CT; Checked all, still no go. Could it be the light dimmer on the dashboard? Would you know of a diagram for it? It seems easy to pull out but not to disconnect.
CTScott
10-07-2012, 08:19 PM
I don't believe the dimmer rheostat is the issue, since it is only used by the cluster when then headlights are on (and in that mode your backlight works).

The wiring diagrams are downloadable from the Micro Image forum (http://www.microimageonline.com/forums/showthread.php/4232-YARIS-FILES)

Do you have a multimeter?
toyoti
10-08-2012, 09:40 AM
Yes I have a multi tester. Itīs a bear to use under the dash!! Iīll be downloading the schematic later on todau. I appreciate your help.
CTScott
10-08-2012, 09:52 AM
Yes I have a multi tester. Itīs a bear to use under the dash!! Iīll be downloading the schematic later on todau. I appreciate your help.

Rather than checking voltages on the dimmer rheostat, start with checking them at the connectors on the cluster.

Specifically, on the right side connector, check the black wire on the top right for 12 V (the brown on the bottom left is ground).

Also check the blue next to the black for 12 V as well.

Also, measure the voltage on the grey and yellow wires with the headlight switch both on and off. Those two wires are the input to the cluster from the dimmer rheostat.