When the headlight switch is turned on, the dashlights fail to come on, would this be a fuse issue, & where is the fuse panel located. Also which fuse needs to be replaced?

It could be, here is a link for the owners manual that should show you were the fuse panel is located, (copy and paste)....http://www.toyota.com/owners/resources/owners-manuals

Thank you, very much! Your suggestion pointed me in a direction which allowed me to get the info which I was looking for. The problem has been resolved!

my Yaris alarm for the headlights when left on, door open failed, and it cost me $450 even though it is under warranty. Ken Mills Toyota massive fail, the warranty covers nothing

I'm guessing it was simply your dashboard dimmer control, under the steering wheel. I had this 'issue' when I got my Yaris. Then I found that control wheel, and what it was lol.

Dash lights and speedometer lights don’t work. On my 2010 Toyota Yaris.

Interiors light are on, but when I turn headlights on, my dashboard lights go out. Any ideas