kajman

Just to close the loop on this - I finally tracked it down. After the relays tested good I was hunting for the Theft Control ECU and noticed there was a unit behind the fuse panel on the firewall with one connecter half way out. I pushed the connecter back in and walla....the windows all worked. It was the Theft Control and the connector was the one that supplied power to the relays to operate the circuits. And so far since I did that, my traction control light stays off (used to stay on all the time). Not sure if related but happy none-the-less. And I learned quite a bit about the electrical of the car along the way. -Kai

Well - those screws to get the fuse plate out are more of a pain to get to than i thought. And I'm thinking the relay is not my problem since my problem involves both the sunroof and power windows and they are on 2 separate relays. The only common thing is the 30 amp Power Window CB (which operates all power windows including sunroof according to lexus manual) which I checked and it is not tripped and also has 12.6 volts running across it but neither the power window master or the sunroof has any power. But based on the attached wiring diagram, the CB sends it's power through the relay which is operated by the Theft Deterrent ECU. 1) Is it possible the theft deterrent is not opening the relay? If I could locate it I'd check for power off the pin going to the relay. I haven't noticed anything else not working. 2) This schematic doesn't show pins 1 and 2 on the master control switch but the moonroof one you sent me had them going back to the same theft ecu. Tied in to the door lock switch I think. Is that possibly part of the problem? 3) It seems odd that there is no power and it used to work until the battery drained. Would a drained battery affect the Theft ECU? Unless the power window relay also sends power to the sunroof relay, this just seems to be a problem related to the ECU otherwise I spose the power relay could be the problem (hoping not to have to pull the fuse panel). Besides the under-dash panel, what exactly do I have to drop to get to the screws that allow me to drop the fuse panel? 2008-11-08_191416_ls_window_schematic.pdf

i know the bolt you are talking about - i was half way there but didn't think of anything underneath the junction box and didn't remove all the way. did you attach something? i don't see it. you still suspect the battery even though it has 11.8 at rest and 13.5 when the car is running? i can try the battery route - just don't have one laying around at the moment.

Lockout PB has been tried both ways. I checked the battery - 11.8 just sitting there and 13.5 with the car running so i think the battery is fine. Which fuses and relays would be involved that would affect both the power windows and moonroof? I know there are separate relays but do they both use the same 30am circuit breaker in the passenger fuse box? I checked that and it was good and also had power going through it. From what I understand on the wiring, with the key on the theft deterrent ECU powers the relay for the power windows and allows the circuit breaker to send power down to the master control switch on the drivers door. I have power at the circuit breaker but no power at the door leading me to believe the ECU has something to do with it (checked it's fuse and that is good too). I'd like to check the main relay for the power windows to see if that is working but I'm having a difficult time finding it. It is sposed to be on the fuse panel in the passenger compartment but there is nothing obvious plugged in that I see other than fuses and circuit breakers. Anyone have a diagram of where this main relay is located on the fuse panel? or back to my original question - what fuses and relays would be involved in affecting both power windows and moon roof? -kai

Didn't think of the battery as the car was starting fine. But it does make me wonder. After starting fine, we had left the car sitting for about 5 weeks a couple months ago and the battery was dead (or close to it). Seemed to be having a problem taking a charge on the charger high setting w/o getting an error so I charged it on a lower amp and it fully charged and then it started ok even after sitting for a 10 days. But when I check the voltage at the circuit breaker and fuses I sometimes got 10.5 and sometimes got 11 volts. Wonder if the problem is really a bad cell on the battery? Didn't really suspect it as it was only about 2 years old. I'll put the volt meter directly on the battery and see what I;m getting and then go get a new battery

At some point in the past couple months, all the power windows stopped working on my 92 ls400. Fuses and circuit breaker appear to be ok. I have the wiring diagram and have tested power at the circuit breaker (ok) and power at pin 9 in the connector for the master control switch. With the key on, pin 9 has no power. I suspect the power main relay or the theft deterrent ECU that activates it but I'm having trouble locating the relay (not sure where to look). Is there one relay that controls both the power windows and moonroof and if so, where is it? Or is there something else I should be looking at? Any help would be appreciated. - Kaj Moenck