instrument panels won't come on until car is completely warm - is this usual

no

Actually... this is somewhat "normal" for pre-1996 Lexus LS400's, especially the 93's and 94's for some reason. There can be a few different reason why this is so, but I think the main issue is within the circuit boards. If you let it go too long, the instrument cluster might not come back on (until you repair it) and your odometer will not keep track of miles driven. There is a guy by the name of Jim Walker who is an electrical engineer and can fix the problem for a couple hundred bucks (opposed to 1400 - 2000 at a dealership). He is very experienced with this issue and has repaired dozens of instrument panels. If you google "Jim Walker Lexus" you should be able to find some contact information somewhere. The first step I would do is email him with the symptoms of the problem. Hope this helps and best of luck to you. - Mark

Very much so. My 91 LS400 starts dim and brightens up within the first few minutes of running. It's been ongoing for as long as I've owned the vehicle, and has never "hurt" anything. That being said. The damn climate control loves to black out in cold weather, but comes back in the summer. Very annoying when you can't tell the time or the temperature!

possibly a bad electrical system. how long is warming up? my 90' ls is more and more sluggish starting these days and my dash is dim when i start up, but after a few seconds it becomes bright again. but mind you only like 10 seconds or so (its also winter here in upstate new york and it gets cold out)

Mark above is right on - I had same problem - and sent it off to have it refurbished - the guy did a fantastic job - runs like new. Lights took forerver to come on and in my case the gas gauge was inop - he fixed all these issues -- the black out on the lcd is different issue - there are folks out there who will swap your bad one out for a one that is refurbished.

My 94 LS 400 does the same thing. It will normally come on in 20-30 minutes. I can see the Tach, Temp Gauge and Speedometer needle working but the fuel hand doesn't work, and I don't know if the odometer is working while the lights are out. Mine only does it in the morning, the rest of the day it doesn't give me a problem. I'm going to record my mileage at the end of the day and see what it reads when the darn thing illuminates. This should be a recall item since dang near everyone is having this problem.

on my 93 ls400 my lights work in the dashboard however the gas gauge keeps saying empty ? is it a circuit replacement or is it someting that a fuse can fix????