oldskewel

iTrader: (1)

Me again. I still have this problem. I was not able to get my photos to work, apparently. But I can confirm my '91 looks identical to your car. The green wire with the thicker insulation and black electrical tape looks EXACTLY like mine. To be exact in what I did, I spliced a Tee off that wire and grounded it to the ground screw also seen in your photo. With no effect.

dc893

I tried the green wire coming out of the door to no effect, if anything it's worse than before. http://en.allexperts.com/q/Car-Alarm...3-Lexus-LS.htm

Pulled the #5 fuse which says anti-theft system and that didn't turn it off either. I wanna choke whoever designed these alarms!!

I have been searching around google and have found that it seems like a fairly common issue, people who have fixed it just refer to the magical green wire that did nothing or no answer has been put up.

dc893

Think I may have gotten it figured out. I still need to put it back together but it is getting late. When I go to put it back together I will post pics of how I grounded it and what wire it is exactly.

I really hope I've gotten the alarm to not go off at all hours of the night. I'm sure my neighbors will appreciate it if I have gotten it off finally.

oldskewel

iTrader: (1)

I hope you've got it figured out. Here's another try at posting my image. This is a '91, and tee'ing off that green wire and grounding it to the ground screw does NOT work.

dc893

You definitely have the wrong green wire.

In the first picture you can see the wire you grounded. You can see the blue plug above it and you will need to remove that black plastic/tape that covers all of the wires and you will see the green wire you need to ground in picture number two. I only grounded the one side of it and not the T method described earlier in the thread. Let me know if that helps out.

BenjiB707

Hey thanks for all pix and input! But I see the wire under the blue plug, So basically you cut that wire, then splice a piece of wire to that and ground it to a screw? What about the other piece of the cut green wire? should I do anthing with that? Thanks

dc893

Another member had grounded both ends and that worked for him but I only grounded the one side. The other end of the wire is dead once it is cut so I just left it. If you want you could just wrap some electrical tape around it.

dicer

So does anyone have some good clear pictures of the wire location? And good clear pictures of what end to ground if its not a tee to ground. Saying ground one end and not the other, is fine if a person knows what end to ground? If there are no pictures then describe the location of the end to be grounded. Is it the one that comes from say the front or top or plug or what ever. I have not even looked yet so I have no idea.
The last photo above with the lower inset picture is okay, but where is that bundle in the big picture that needs to have the focus done better.

oldskewel

iTrader: (1)

I finally got around to this today and it worked!

'91 LS400

Here are complete instructions:
- slide the driver's seat all the way back to make room
- pull the carpet that is to the left of the left foot and near the door frame back until you see the blue connector as shown in the above photos
- in that connector there are about 8 wires that are green plus something else (dots, lines, etc.). But exactly one wire is solid green. That is the one you work on.
- use a utility knife to carefully shave off enough insulation from that wire so you can wrap another wire around it.
- wrap another wire around that now-exposed segment of green wire. This makes a Tee. Solder, heat-shrink tubing, electrical tape, etc. depending on how nicely you want it done. It is a ground wire though, so pretty safe.
- ground the other end of the grounding wire to the chassis using one of the bolts as seen in the above photos.
- plug the connector back together, put the carpet back in place, and you're done.
- the security light (slow flashing red before) now does not come on, and the alarm is never activated.

EDIT - This will disable the alarm system, but it will also disable the ability to unlock all 4 doors with the driver's door key. 2.5 years later, I debugged that problem and found it was this alarm disabling that killed it. Confirmed it by removing the grounding wire and suddenly the door unlocking worked again. I went back to disabling the alarm since I'd rather never hear that again than use the key unlocking feature.

SEBASS

Thanks guys for detailed instructions. I just did this and I believe my parasitic draw has came from alarm as now i think it's stable at 0.15 mA so it should be ok now. Thanks for this easy fix. It took me a year to figure this out but i was lazy about it so that's why.

Dwightjr

Can factory alarm Immobilize engine on a 1991 Ls 400?? Will bypass solve the issue?

dicer

It immobilizes the starter only, the owners manual tells how to disarm it.
Most any problems with the alarm are because of bad switches. Like the deal where you use the key to open the driver door and it sets off the alarm.

Here is some good info, and it also has info on other year cars too.
http://www.the12volt.com/installbay/...tail/1280.html

See1

So I lost the old remote it came with & sometime out if nowhere it'll just start going off. Do I turn the switch to remote on or off??

dicer

The remote switch on the dash is to turn on or off the remote receiver in the car. If its on then anyone with a system to mimic the remote could unlock the car. Plus it takes battery power to operate and is why the owners manual says if its to sit for long times to just turn it off.
It really doesn't affect the alarm as far as I know. What causes the alarm and security system to activate is the hood, trunk, and door switches. If any of them are not working correctly then the alarm is going off. Either the problem is with the switches or the connectors or wiring or even the alarm ecu itself, I would think it could be plagued with the same capacitor issue that the engine or power train ecu has.

oldskewel

iTrader: (1)

Update on this alarm disabling ...

I found out today that on my '91, this procedure to disable the alarm has the unwanted side effect of disabling the ability to open all 4 doors from the driver's door key cylinder. I debugged that problem, removing the door panel, etc., and found it was this alarm disabling that killed it. Confirmed it by temporarily removing the grounding wire (undoing this alarm disable) and suddenly the door unlocking worked again.

I went back to disabling the alarm since I'd rather never hear that again than use the key unlocking feature.

Hopefully this knowledge will save someone else the two hours it took me to figure it out.