strongsail

My '93 SC4 has the stock alarm system, which has developed an annoying problem - when the alarm is set and the trunk is opened with the key, about one time in 10 the alarm sounds and scares the **** out of me. I have gotten in the habit of using the remote to unlock the doors and turn off the alarm before opening the trunk, which is a pain, and it just irritates me that it isn't working right.

Anybody else had this problem? Any ideas on fixing it? Thanks!

GS3InPhx

Just a thought, but have you checked to see if the truck light still illuminates when it is open? That is normally on the same trigger as the alarm uses, fix that and you'll probably fix your problem. I'd look at the latch for the pin switch.

strongsail

GS3InPhx, Trunk light works fine. Good idea though.

The owner's manual says the alarm will sound "if a door or the trunk is opened without using the key" - that seems to indicate that there is also a sensor switch in the key lock in the right taillight. I will check both places and let you know what I find.

engin_ear

iTrader: (1)

Funny (NOT!), my '88 Supra has done the same thing from time to time. Not fun when it happens at three in the morning!

It may be due to an alarm circuit timing thing, which every so often causes an error. Otherwise, lubrication may help.

strongsail

well hopefully I will be able to troubleshoot it soon - finally did the deed and ordered oem repair manuals and wiring diagrams - will have a chance to look 'em over when I get back from vacation - btw, the local Lexus dealer quoted me $225 for all 3 books, I ordered them from Carson Toyota, $135 +ups.

DevilDog

I know!

The rod from the trunk key cylinder to the latch needs to be shortened. The rod is popping the trunk latch before the sensor behind the trunk key cylinder can make contact. To verify this, put the key in the trunk key cylinder and turn it VERY slow. The alarm will probably go off.

Hope this helps!

DD