raybear

Hi guys am new to the club i have lexus ls400 gen2 2000 model i cant figure out this issue in need of some help please

i have no climate control working its fozen on a/c mode on screen with a weird flashing demister button on too. Nothing is working not even a/c even though its button selected. Its the touch screen stereo model with sat nav, everything on the unit works radio sat nav.. But climate control, once u push climate button to go to climate screen theres no fan ,no heat, no touch screen responding on climate screen, but on every other screen functions everything works ie sat nav radio so on. I checked all fuses and found the 7.5 a/c fuse keeps blowing under steering wheel changed it blows again, switched relays under bonnet no change, i uplugged a/c plug on a/c pump no change still blows, i toke ecu out and fuse box to check any leaks ie caps or water ingress nothing . I got car plugged in on diagnostics showed no faults but not reading a/c unit as think cause fuse is blown. Please can someone help cant drive my car as windows fog up and its super cold .. Many thanks

RA40

iTrader: (6)

Has the car had any electrical work performed? Something in that A/C circuit is grounding out causing the short. Will have to check each of the wires to determine which one is causing the fault. Yamae may have other insights for the control unit.

raybear

cheers for reply buddy cars never had any work done since i owned it & was working no issues before , i couldnt find much info out there of similar issue its weird everything on unit works bar climate, if i could get fuse to stop blowing i think climate will work.. well i hope cheers

Yamae

The 7.5A AC fuse supplies +B 12V to the A/C computer and servo motors. The important first step is to check those finding which one is drawing the big current. The problem is that it is not easy to access those because those are under the dash.

raybear

hi again is the a/c computer control the heat and fan speed ie reply what does it look like and cant see any links pics out there for gen2 ls400 location of servo motors .does a/c control everything ?

YODAONE

Have two spare Climate control heads which integrate the amplifier board...

I replaced capacitors in mine....it seems to behave better (when pressing "ON" button there is more consistency of what comes on...like air conditioning compressor that I did not activate...) and replace climate control bulbs;

See:

https://www.clublexus.com/forums/ls-1st-and-2nd-gen-1990-2000/855424-1995-2000-ls400-climate-control-capacitors-and-backlighting.html

Imspect, clean and, or, replace your temperature sensor

See:

https://www.clublexus.com/forums/ls-1st-and-2nd-gen-1990-2000/846574-interior-temperature-sensor-1995-2000-ls400.html

DFHEEZY

I'll provide updates if I find a solution, but my 1996 LS climate control system appears to have died today. The screen has illumination, but that is it. Outside Temperature indicator also reads _ºF... The fan has stopped, AUTO does nothing, even the defroster is unresponsive... I checked a bunch of fuses and things appear to be fine otherwise... I need to keep looking...