'97 Avalon strange flickering headlights

[AutoJohn]

I'm searching everywhere for an answer to this weird problem, haven't found one yet.

-Headlights start flickering very fast, but -only- above 55mphish, continues until I slow down.
-Dealer replaced battery, said nothing else wrong, now out of warranty.
-No flickering below 50 or so.
-Bumps, etc. do not start, interrupt or stop flickering, which is intermittent but continuous every two seconds or so.
-Flicker is very fast, not like something loose.
-Revving engine to 3000 or so while in park produces no flicker.
-Reseated all relays, fuses.
-Taped down all wiring in case wind caused something to short.
-Searched web for recall/notice but found none.

Again, I can drive around town at below 55 or so, bumps, wet, dry, and lights rock solid steady. Sounds very mysteriously electronic/computer in nature due to the point it starts, and the consistent pattern of the flicker.

Have run out of ideas, and hate to take back to the dealer. I know they're going to start replacing things for $$$$ until they find it.

Any thoughts or advice would be appreciated! Thanks!

John

[yotatechie04]

Maybe the bulbs themselves are bad? I've also heard about the electrical harness that the lights connect to shorting out, getting wet, and going bad.

[resmo]

Why don't you see what rpm you are running at 55-60 mph. Then while parked hook a volt/ohm meter on the battery, have someone rev the car and hold it at the rpm you found. See if the voltage varies at a constant rpm and see if you lights are flickering. I suspect you will find trouble in the alternator/voltage regulator system. One other thing to check is the ground side of your system. Clean all point with a wire brush on the negative side. This is the easiest and quickest thing to check. Hope this helps.

[wilnwil]

Was wondering if you found what the problem was with your flickering headlights, we have exactly the same problem....