Dash lights are not on when daytime running lights are on.

I did not think that dash lights would be on with DRL, what is the point? Check your instrument light dimmer switch to see if the dash lights were accidentally turned down.

No, if the dimmer was turned down, the dash lights wouldn't work when the headlights are on. As I said, the dash lights DO work when the parking and head lights are on. They used to work when the DRL were on. The dash lights are on in my Camry and my Yaris when only the DRL are on. The fact that they used to work on my Highlander and now they don't, tells me that there's something wrong somewhere.

There may be a relay or electronic device somewhere that controls the dash lights. Good luck but if it were me I would not worry about it. I prefer the dash lights to be off during the day.

just wondering if you fixed your problem as my 2013 Highlander is having problem with the instrument panel lights going completely off, and then coming back on!

I have the same problem with my 2007 Chevy Silverado 1500. Yes I understand most people think "why, what's the purpose?" Well, my gauges have a dark background and the markings are white but not that white, even in the daylight the dash is so dark, I can't make out what my speed is or how much gas there is in the tank. It's really surprising just how dark it is in the daytime. I am thinking that there would be something with a relay since they work with parking and head lights at night.

I can't believe it took this long to find. The DASH BOARD dimmer on the Highlander (1996) is the same button as the Odometer setter on the dash. If you push the odometer knob down and turn it, it re-sets the mileage. If you DON'T push it down and just turn it, it adjusts the dimmer lights!!! My wife is happy again and my son is impressed!!! :)

I know the dash lights should be on when the DRL are on. That is not debatable. I have a 2006 Highlander and that is the way it works. My daughters 2005 Highlander has the same problem that you have. Her instrument cluster lights only come on when the park lights and/or headlights are on. It is very difficult to see the instrument cluster during the day without illumination. I am still looking for the 'fix'. I am going to look into the dimmer switch on the steering column. You know the thing you use to turn on your park lights or head lights.(sold as 'dimmer switch' at Rockauto - https://www.rockauto.com/en/catalog/toyota,2005,highlander,3.3l+v6,1431009,electrical- switch+&+relay,dimmer+switch,4340 ) The lights should be bright during the day and dimmer at night so the lights don't burn out the back of your retinas. If I find the problem I will post it here hopefully sooner than later. :)