Alarm System

[mrnickleye]

I am currently researching the simplest way to by-pass the Factory Theft Deterrent System.

If anyone has done this, please feel free to jump in with your input. After I have figured it out, I will do a write up for the FAQs section.

When it is activated, the starter relay is immobilized until the door lock is locked and unlocked with the key. The horn honks and lights flash for about 1-5 minutes.

I have, over the years, read about adding a starter button to crank the starter. This is not necessarily the best way.

Also, I have read about the horns and lights coming on at random times using that method. Not wanted !

For those interested, and understanding of wiring diagrams, check these pages out and let us know what you think.


Looks like you could permanently ground the starter relay at terminal #3 to by-pass the Theft Deterrent Computer (TDC)
http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=122

http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=038

http://www.cygnusx1.net/Supra/Librar...px?S=Main&P=22

Also perhaps cut wire to #6 terminal on TDC to eliminate current to headlight circuit and alarm horn. ?? ..

http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=123

It looks like the TDC is buried up under the dash, so getting at the correct wires to cut may be near impossible.

OK...after an hour of research, it appears you can unplug, or remove, the TDC. Then ground the #3 terminal of the starter relay in the Rt. kickpanel, which will allow starter operation.

Any input???

[toyfan420]

Originally Posted by mrnickleye

OK...after an hour of research, it appears you can unplug, or remove, the TDC. Then ground the #3 terminal of the starter relay in the Rt. kickpanel, which will allow starter operation.

Any input???

You can do this and it works. Unplug the harness from the security system. You can either ground pin 18 (I think) on the harness, or you can do what you described. I just made a little harness for the starter relay to plug into, and grounded terminal #3. This is MUCH easier than trying to find the correct pin to ground in the security system harness, as this is up inside the dash area.

[Kevyota]

I have an 87 (Non Turbo) Supra...

Does this work for that model too???
My damn alarm goes off randomly... day or night & I NEED to disable it.

Also, everyone refers to MK1, 2 & 3's...
What do I have???
Sorry for the dumb question.

Thanks,
Kevin

[Busted Knuckles]

It should work. This is the diagram for the MK III Supra. Question, tho. Where is the TDC located? I suspect under the dash board, but is it left of the steering column, or right? Up against the firewall, or closer to the gauge panel? Just unplug the connector, then ground the #3 relay terminal. Sounds easy enough.

[Kevyota]

What does the box look like?
I can't tell which is which... there's Black & Blue Boxes.

I'm assuming it should have 10 wires?
or are they different from year to year???

Thanks

[thomasz]

I will find and try to do it.

[burton51m]

Here's how to disable the stock alarm...

SupraMania - View Single Post - My damn factory alarm...