1990 Lexus LS 400 - 126K - No problem since recently purchased.....
Drove last night with eat working..... Arrived at my destination
and when leaving the heat would not turn on, make any noise when buttons are pushed......

I have been a lexus owner for the last 9 years (Sc & 2 LS4)
I have been on to Lexls.com with their very helpful tutorials
and Also searched for any answer to this i can find.... But keep coming up with the LCD black out issue - which is not the case here....
The reason i brought up LexLs.com was because I have done the A/C diagnosis code search on my old LS - and when i tried it on the new LS all the lights, light up an beep
But the problem is that None of the buttons work..... Only when i hold down AUTO & RECYCLE AIR BUTTONS

Please help
Thank You

 

Does the LCD not work or is there no power period... you should check fuses of course and go from there

 

I Replaced the Fuses - there were no bad ones as far as i can tell. (never done any of this before)
I tried the fuses - circuit breakers -
Now today - The Radio Controls Dont work either out of the blue
The screen lights up on the radio and the antenna goes up and down but the Volume/Power button is loose and no control and no sound to the stereo - literally in the blink of an eye.

I went to Advanced auto and the guy came and said oh the LCD is probablt blown - This isn't my first LS they all go... thats not the issue
I am not electrically savy - brough to a mechanic to look at it and he sent his helper who basically had me show what is wrong and said they need it for a few days - (At first he said a Week)
I don't know what to do -
NOW no radio or heat/Ac control

 

A few days?? For what? If They're gonna charge you alot of labor, you should just pick up a used one from the junkyard that works, it'll be cheaper. The radio ****, I think you can pull off the ****, and if it's like the old school radios, there should be a nut there that you can tighten up which will get the inside to contact again. I have no idea on the HVAC, sometimes mine doesn't blow. I don't worry about it b/c I know it will kick on when it wants to. Try pulling the HVAC unit out and check the wiring behind it. Here's a tutorial on how to pull it. http://www.lexls.com/tutorials/audio/headunit.html
Here's a used one on ebay but ya never know what you're gonna get.
http://cgi.ebay.com/ebaymotors/90-91...item2a0f551b03

 

I'd say to check two things, the ground on the dash harness, and the rear deck lid harness..

http://www.lexls.com/tutorials/lighting/bulbout.html

Also did you check the relay's on the top of the interior fusebox? I had a problem with a relay here:

https://www.clublexus.com/forums/ls4...ights-out.html

 

my 96 ls400 is having the same issues and i just ordered my preowned ac/heater control unit it was just $131.67 suppose to be picking it up today and installing it...

 

Yuyo - how did the new control unit work out? I'm having the same problem