92 Ls400 Electrical Problems !

[Claudel]

Hoping someone can help...

I own a 92 LS400 with 97K on it (original) and no major issues..until now...The other day, I start the car, pull the lights on (I live in Canada) and whent to the corner store for beer and to my surprise, the car didn't shiffted...It was running only in first gear !!! I also noticed that my cluster was showing that the car was in "DRIVE" and also in "REVERSE" !!! Both lights where on...When I got back home, I pull the lights OFF, the cluster did show "DRIVE" only and the gears where shiffting normally...Then, the other day, I did open the trunk with the remote button in the car and when I got back home, the remote button wasn't working anymore...I know it's an electrical problem but wath does this have to do with the car not shiffting with the lights on...Honestly, I really don't know where to start...The cluster have been overhauled 18 months ago and work's fine...

Your comments would be much appreciated,

Claude L, Montreal, Canada,

[landar]

Claude, there is a well known problem with 90-94's which has to do with the trunk wiring getting stretched and becoming intermittent. It causes all kinds of strange electrical behaviours and *could* be your problem(thats where I would start). Have you ever had your trunk wiring repaired?

[Claudel]

I Landar,

Thanks for your prompt answer...However, I don't know where is this "trunk wiring" located !!! Is it in the inges or else...Also, today, I noticed that the "burn lights" warning (for the rear lights) in the cluster did lighted when I push the brake pedal and after a full check-up, there is absolutely no burned lights nowhere to be found...VERY STRANGE like you said...And I'm curious to know what relation this wiring has to do with the transmission not shiffting and staying in first gear, when my driving lights are ON...

Thanks again,

[landar]

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

[Claudel]

Thanks again Landar,

I just checked the link you did send me and I will surely "get into the trunk" of the car and verify every single wire that I can find in this harness; I'll keep you posted on any discovery and result regarding this "operation"...

Many, many thanks for your help...

Claude L,

[Claudel]

O.K....I just look inside the trunk and everything is "so clean" inside this trunk, that I absolutely don't know where to start to put my hands on this wiring harness...The inside trunk lid is covered with a "grey molded carpet" that is hold in place by ???? How in hell do I remove this liner !!! push, pull, unscrew or what...I suppose that the wiring harness is behind this liner and if not, then, when I look at the left side hinge, there is a black rubber filler running center to the metal hinge and going inside the carpet liner...Is this harness passing inside the hinge and going inside the trunk lid liner !!!

As you can see, I'm no mechanic but I really want to try my best to resolve this problem without having to pay $$$$ to my Lexus dealer...There must be a diagram somewhere that I can look at or instructions so that I can go from there...

And again, BIG THANKS FOR YOUR HELP...

Claude L,

[Garo_mcc]

Claude, try the link below, seems it can be a common occurrence.

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

Good luck!

[steve2006]

I found this by searching pictures of "Lexus LS400 trunk hinge wiring" within 30 seconds.

Follow the hinge back and you will see the wiring loom concerned wrapped up in black tape carefully remove the tape to expose the wires and then check each wire carefully, IIRC the white wire is the normal culprit then follow the repair instructions provided on www.lexls.com

You will probably find the easiest way to work is to lie in the trunk and have a decent flashlight to hand.

http://s731.photobucket.com/user/rojo412/media/Stereo%20Howto/DSCN0018.jpg.html

[landar]

The wiring loom is routed through the left hinge area. Just work the harness free and unwrap any tape to expose the wires. The lexls.com tutorial mentions the white wire as being the most common failure. You have to look carefully at all of the wires because at first glance they may look ok, especially to the untrained eye. But all it takes is a small nick or pull and the wire inside can be stretched and broken. If you find a break or suspicious area of the wire, your job is to secure it back together(soldering iron would be good).

[Claudel]

O.K. guys...Saw the photos that "Steve 2006" sent and also the further instructions from "Landar"...Will go from there and keep you posted...Wish me luck...

THANKS AGAIN,

Claude L,

[fsuguy]

Hi,

If I remember correctly, there are two black plastic pins/plugs (I'm not sure I am calling them by their correct names) that are pressed into the trunk lid and they hold the carpeting in place. You should be able to remove them fairly easily by levering them out a bit with a flat blade screwdriver.

The wiring harness runs from a fairly thickish bunch of cabling on the back of the luggage compartment at the left hinge, and a smaller harness branches off this main one. The smaller harness is routed through the left hinge and is hidden by the black plastic/rubber cover (it comes off easily). It may take a while to find a broken wire since if the insulation on the individual wires is not broken you may need to use some ingenuity to identify a break. Sometimes a broken wire may be indicated by a limpish wire; alternatively, if you can use a VOM and a sharp needle you should be able to track it down without resorting to cutting all your wires to find the break.

Good Luck!!

[Claudel]

Thanks "FSUGUY" for the complementary infos...very useful details regarding the rubber/plastic hinge cover...I'm still working on finding any faulty wires...

Regards, Claude L,

[Claudel]

Guys...

Because of ALL OF YOU that did HELP with your comments and suggestions...YOU WHERE RIGHT ON !!! Like you wrote, I did find 3 wires cut off from the harness....THE WHITE, BLACK AND ALSO THE YELLO WIRES where all splitted and hanging there in the far left corner of the trunk !!! I still have to complete the soldering of these wires to fix the problem and I will keep you posted on the result...

SO...BIG, BIG THANKS AGAIN TO ALL OF YOU...

Regards,

Claude L,

[Zburns82]

We are having electrical issues with a 92 LS 400. It is causing the battery to die and we just replaced it and the new battery is already dying. The alternator and starter are all good so i started realizing the other little electrical issues through-out the car, including trunk lock issues. We have just been using the key to open the trunk and dealing with the other small issues but now i need to make the repairs due to the battery issue. Is there possibly a fuse I could just pull that would eliminate the trunk issues from the rest of the car or will i need to track and find the repair in the wiring? Thanks for your help in advance and glad Claude was able to get his problem solved!