I have a 1993 lexus ls400 and are currently having problems. My ac and radio do not turn at all only my clock comes on. Also I am having problems with my dash, it flickers on and off and gas gauge isnt working. I have read threads about instrument cluster not working when its cold but i live in florida its always HOT. Any suggestions would help on how I can fix this myself ???????

 

Iｔ sounds like an AM1 line not properly working to me. AM1 line supplies 12V to the radio, to the blower motor, to meters and etc via the ignition switch. I suggest you to check this line. The actual items to do are
1. to check the 40A AM1 fuse and the terminals in the FL box,
2, the in /out conductivity of the ignition switch of AM1 line,
3, to check the cable in between above fuse and the ignition switch.

This was just my experience but the highest possibility would be the ignition switch itself.

 

Do you know where i can find a diagram to show me what I need to be looking for?

 

Regarding the English version, sorry to say, I have no idea. I only have a Japanese version and the attached is the related part. The blue line is called the AM1 line. Sorry that I only have this much for you.


Is your problem intermittent? If so, the contact points of your ignition switch are not in the good condition. One idea to clean the contact points of the AM1 line is to set the electrical loads max such as the blower motor full speed and the wiper on and then turn the ignition key on and off several times. Big currents blow dusts and the problem is fixed sometimes but not always.

 

ur ac head unit is out and u also need ur cluster repaired or replaced.

 

Cluster needs to have 3 capacitors replaced. That usually fixes the intermitten flickering and nonfunctioning gas gauge.

What do you mean your AC doesn't turn on? Does the LCD not show numbers? Or does it not blow air? The LS climate display's LCD dies (blacks out) partially or fully. Pretty common.

Radio, stock headunit? Possibly dead. Checked fuses and wiring already? May also be cause of AC issue if the AC is nonfunctional.

 

The whole console where the radio and ac are doesnt come on at all. Iv echecked all my fuses i havent checked wiring yet. Do you know where i can find diagram of wiring?

 

would the ac head unit cause the radio to not have power either?

 

It's possible. The harness are right next to each other, perhaps some damage was caused somehow or alterations by a previous owner hastily reverted to stock for sale... Also I'd recheck the fuses just to be sure, make sure the right spec fuses are installed and look closely to make sure none are blown. Service manual can be found easily on this site, there is a link that takes you to one posted online that includes wiring diagrams as well, free and I want to say was recently bumped.

 

https://www.clublexus.com/forums/ls4...ar-demand.html

as part of the FAQ thread;
https://www.clublexus.com/forums/ls4...ls400-faq.html

 

greatly thank u for u help

 

I have a major problem as well. but I know it has to be a simple fix.... I took battery out for a couple days to change timing belt and water pump, well I had no accessory power lights, seats stereo, windows, just everything but it would crank up and run like a top...I checked and changed the 120a alt fuse under the hood and now the only voltage I have is just the battery, not even to the fuse block with and without key on..any pointers

 

No pointers yet, but as far as disconnecting the battery, I do it constantly. There are a few rules to doing it though, 1 is no key in the ignition switch, all windows up and doors closed but not locked, moon roof closed, and same with plugging it back up. I suppose the windows could be down to work on them.