Alarm System

mrnickleye · 07-18-2007, 06:06 AM

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???

07-18-2007, 06:06 AM	#1
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	Alarm System 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??? __________________ Had a Red 1989 N/A. Automatic. Sports Pkg. w/wing. TEMS, and some nice MODS. Sold to a friend 10/08/08. Last edited by mrnickleye; 07-18-2007 at 06:31 AM.