A/T Temp light flickers/flashes 1999 running normal otherwise

So: 1999 T 4Runner Sr5/4wd
Was on a trip and had been driving for 40 miles at 65 mph on cruise when the A/T temp light started flashing. When I'd take my foot off the gas it would stop IMMEDIATELY.

So, therefore, it was always happening on cruise.

So I looked it up and noticed other people had similar problems at same speed/distance. The yesterday when I started it, let it warm to operating temp it started flickering again. There is no pattern. This isn't a blink it's the briefest of flickers. Then it will go dark, and flicker again. It seemed almost to match up with small bumps on the road (I live in deep country), and thought it might be a loose wirre. But if it were a loose wire, whether I had down on the gas or not would not matter.

The car runs in perfect margins everywhere else. SInce I bought it a year ago, although the vehicle has 230,000 miles on it, thos one-family-owned 4runner shifts and drives smooth as ˟˟˟˟ from a duck's ass. The tranny has been a little noisy since I bought it. A problem I remedied when I took the center cabin/plastic housing off the shifter and found that the boot there was torn. Contacting the guy who'd sold it to me he told me the tranny had been replaced in 2002 (it's a 99) and it had always been (very) hot around the shifter. You could warm a cup of coffee it had been so hot. So I insulated it. To no real immediate effect, except reduced cabin noise and temperature (what I'd wanted). I am SURE, at the very least the fluid has not been changed in 50,000+. The last owner, who had inherited from sister seemed to take her for granted. The fluid is a "normal" red and the level is perfect.

So there I am with a perfectly running vehicle with a blinking/flickering a/t temp light with no other symptoms except it stops when I take my foot off the gas. Again, it began on a longish trip. Yesterday it started out of the driveway. No way it could be overheated that quickly. RIght?

I fear the worst.

*The vehicle has some rust. A few weeks back I had a coolant leak. It was from the rear heater return. I by-passed to no immediate effect. Save for stooping coolant drip. Which had been my goal. I searched five states for a good Sr5. This vehicle means a lot to me. As a side note, I saw a LOT of them over 175,000 miles.

SAW THIS ON FORUMS