92 Ls400 Climate Control Panel Problem

[threepwood]

I have a 92 LS400 with a strange problem. After coming back from a 1 week trip in which the car was just sitting in an airport parking lot the entire climate control panel was dead when I started the car. No fan, no A/c, no response to pushing any button. I drove home with the windows open. Next morning i went out to the store and immediately on starting the car everything worked. Continued to work for the entire weekend. then Monday morning no fan or lights again, completely dead. 3 miles down the road the entire panel mysteriously lite up again and all started working. My radar detector is hooked up to the cigarette lighter and it functioned the hole time. Any ideas what it could be?

[RDM]

More than likely it's a bad solder joint on the board. Temperature extremes affect it, that's why it's randomly working. You can pull it and find the bad joint, have it rebuilt (with a new LCD if yours is already black), or find a used one to throw in.

[threepwood]

More than likely it's a bad solder joint on the board. Temperature extremes affect it, that's why it's randomly working. You can pull it and find the bad joint, have it rebuilt (with a new LCD if yours is already black), or find a used one to throw in.

Thanks, but unfortunately that didn't work. Took the boards out. visually inspected all the solder joints with a jewelers loop. resoldered all the connections to the boards and 2 suspicious looking surface mount resistors. Measured voltage on B, IG+ and ACC, all good. Put everything back together and now it will not kick in at all, ever. The panel lights up when you first start the car and if you're fast enough and hit the low fan button you will get fan for a few seconds then everything shuts down. So I've ordered a new module. In the worst case, I'll get a working clock out of it (mine has been black for well over 10 years). In the best case it will fix it. I have no other ideas.

[threepwood]

I have a 92 LS400 with a strange problem. After coming back from a 1 week trip in which the car was just sitting in an airport parking lot the entire climate control panel was dead when I started the car. No fan, no A/c, no response to pushing any button. I drove home with the windows open. Next morning i went out to the store and immediately on starting the car everything worked. Continued to work for the entire weekend. then Monday morning no fan or lights again, completely dead. 3 miles down the road the entire panel mysteriously lite up again and all started working. My radar detector is hooked up to the cigarette lighter and it functioned the hole time. Any ideas what it could be?

Just to close the loop. The problem is definitely inside the module. Bought a used module on ebay with new LCD. It works the heating and air just fine all the time but has it's own little quirk. With this one everything works except for the two front and rear defrost/defog buttons in the upper left corner. For some reason these don't do anything. Sent it back for a replacement.