Dash backlight disconnected (oops)

[eddiewould]

Hey when installing my headunit today I somehow managed to disconnect the dash backlight (the one for the speedo etc that goes on with parklights).

The car is a 1994 Celica... does anyone know what I've unplugged, and where I need to plug it back in?


I guess its possible I've blown a fuse as well... should check that.
Cheers



Eddie

[Ae92typeX]

Check your fuses cos Ive seen on many occasions people connecting the headunit negative to the lamp wire (as with power off a multimeter reads it as negative). The headunit works fine, but when you turn on the lights the dash fuse blows. The head unit still works so it can be a little puzzling at first.

[eddiewould]

Well there was a fuse blown, but I replaced it but the problem is still there :S

[eddiewould]

On closer inspection the same fuse blew again when I turned on the lights.

Perhaps I have wired up my headunit wrong?

From the factory wiring harness, I've got :

Yellow = constant 12V+
Red = Switched 12V+

now heres the tricky part, I'm using an orange wire :S as my ground.
Orange isn't normally ground... but its the only wire I could get a 12V difference with.

Originally I thought it was the blue one - there was 12V across yellow/blue and red/blue... but when I actually plugged the headunit in, the voltage dropped to about 5V... so I don't think that was the right one.


But coming out of the factory wiring harness there wen't any other colours really! I guess I can tap a ground off the cigerette lighter?

[eddiewould]

The headunit I'm replacing just grounded through the metal frame.

[Ae92typeX]

just ground it to the nearest bolt/screw and try that.

[eddiewould]

Yeah, you were right actually... a mate explained it to me at work


obviously my headunit is grounding through the screws at the moment so thats why its still working... and that orange wire I shouldn't be using is the illumination wire... so that the headunit 'glows' when the lights are turned on.


I'll tap a ground off somewhere else and I should be sweet.


Thanks for the help!