I have an '03 Limited and I just recently noticed that when I drive off in the morning the display with temp, clock etc fades in and out intermittently. I think it goes away once the car's been driven a while, but not 100% sure.

Any clues as to what is causing this behavior?

Mine did that when it was new, though I haven't noticed it recently. Most suggest pulling out the center stack (involves removing everything in front of the console) and replacing the bulbs that backlight the LCD display. The bulbs are a few bucks from the dealer.

mine was doing this last week too. i disconnected my amp, radar, and all accessories i have hardwired thinking they were pulling too much power from the alternator but it still did it. i forgot about it and then checked yesterday and it wasnt doing it anymore. my truck has about 55K so its not a new truck thing, but still not sure why

Mine does it too. frequently , want to take it to the dealer but it's intermittent so you know the answer I'll get from them.

I would concentrate my troubleshooting in the one that we scroll at the left side of the steering wheel, I don't know how it is called. But my basic knowledge call that a dimmer..a rheostat..or a potentiometer. Its controlling the flow of current towards those display lights as you can observe while scrolling it. That type of component gets dirty, changes in temp, and humidity plus molds makes the contact bad and maybe the reason for the insufficient current and voltage supplied to those bulbs in the displays causing it to glow dim.
If its a single bulb thats busted or gets dim, then its the bulb. but if all of them in a module or a cluster gets dim, then one part incharge of the supply messes it. Just like an old stereo, when you first turn it on at medium volume, it just whispher, minutes later , it shouts..My "don't do this at home" remedy is to flush the volume with lighter fluid(it dries fast) to remove those dirt and molds. The volume is the same to the Dimmer in the 4runner.
So I'll do it if the bulbs in the cluster of my 4runner glows abnormally or I'll just replace that thing. The one we scroll may have a belt to the real component that is mounted somewhere.
It just my opinion and may not be correct and still would suggest the dealer to look into it and have OEM replacement..
..the center aircon assy display if thats what you mean is also contolled by that dimmer while the stereo is independent. Try scrolling it up and down(fast) to loosen the dirt and enhances the contacts if it solves your problem.

My temp display does the same thing. Its been doing this for over a year now (off and on) I just noticed it again last week and today its back to normal. So far it hasnt gone out yet. If you do a search, there is a thread on how to remove the front console and clean the contacts.

mine does it sometimes too, it seems like 50% of the screen will flicker while the other half doesnt...
It seemed like mine started later in my truck life, now at 62k....
I thought it may be from the battery losing juice and was planning upgrading to optima anyways.... either way it doesnt bother me TOO much.

Yeah I just noticed this in a vehicle i just traded for. Now after the navi install i notice it a lot more!!

Mine did the same thing too. I took it to the dealer and they fixed it under warrenty. I think they said it would have been around $800 for it.

yea i have a kenwood unit with some audio upgrades thus the reason why i do not want to take it to the dealership.

wondering what they did?

Just noticed mine is doing it also , First problem I have had

Mine went fuzzy on 50% of the screen last year. The dealer replaced the unit under warranty. The list cost for the part was around $900+. I'll look again for the exact part number and cost in my receipts. Wouldn't want to have that go after warranty.

Wish they would just keep it simple on a truck and skip the fancy LCD type screen.