I am new to the site and I am experiencing the same problem. I bought my '94 LS400 in May of 2001 with 36,000 miles. No problems until October 2002...when my dash kept taking longer and longer to light up (and getting worse). I live in Wisconsin, so based on what I have researched so far, I am blaming the problem on the cold and a defective circuit board (If your cluster is totally dark with the exception of the shifter position and headlight-on lights, your "power source unit" circuit board is shot. The part number is 83247-5A050-RP). I just wanted to let you know that I have registered this defect with NHTSA (and I am not the first....and I hope I'm not the last). The rep I spoke to told me that if there is a trend and the defect is severe enough, NHTSA will try to initiate a recall. That is where we come in. Call 1-888-327-4236 and let's get this defect documented.
I was also told that I could petition a recall. Just send a letter to:
US Dept of Transportation
NHTSA
Att: Office of Defects Investigation - John White
400 7th Street SW
Room #5319
Washington DC, 20590
In the letter, document your experience, the dangers of this, include the defect ID from your complaint to the NHTSA (if you can), etc.
I like my LS400 (it drives like a dream), but this is unacceptable to me and I don't feel it is fair, because I live in the northern region of the US instead of a warmer region, to have to give up an 'arm' or 'leg' to get it fixed when it is obviously a design defect.
Thanks for letting me vent,
Driving in the dark in Wisconsin