Disabling Theft Deterrent?

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SupraNoob
Oct 13, 2013
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New Jersey
I just purchased a 1987 Toyota Supra Turbo. The engine is fine; car was turned on before it was bought. The thing is, the previous owner might have had the doors locked and unlocked in such a way that the starter kill did not go on. So whenever he started it, it went on like a brand new car. When it arrived home my sister and I unlocked the driver's door (which has not door handle or lock) through the hole by pulling some lever. Now whenever we try and start it we get nothing, no clicks no sound at all. The battery is fine since it's brand new and all the lights and headlights turn on.*The clock also dims when the switch is turned to on.

I know there's a way to bypass the system:
Locate the theft deterrent box near the steering column.
Cut the blue/orange wire and ground it.
Remove the theft deterrent box.

My question is*do I have to reset the alarm before doing this? Or will the starter kill be disabled as soon I finish the process above?
Even though all my locks are screwed up, I heard there's another way to reset the system, but regardless, I want it out so it won't happen again.

PLEASE HELP. I'd appreciate any sort of advice.The locks in the hatch and two doors are shot so the normal reset method won't work.

Thanks in advance!*
 

supraguy@aol

Well-Known Member
Dec 30, 2005
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Atlanta
Unlock it by the passenger door, and try the starter again.

Oops. Just read your post more closely. Both doorlocks are crap?
 

Dan_Gyoba

Turbo Swapper
Aug 9, 2007
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Ground pin 4 on the starter relay.

http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=122

This grounds by default through the theft deterrent computer, As seen here: http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=038

Grounding that pin directly bypasses the theft deterrent computer and will allow normal starting regardless of what state the TDDS thinks the car is in. Alternately, you can pull the door panel and look for the switches which the key cylinders hit and trigger those, or probably simpler to send a ground pulse to pin 3 on the TDDS computer, which will make it think that the doors were properly unlocked with the key.

Edit: most people permanently disable the TDDS by grounding pin 1 from the TDDS computer. This makes the security system think that the hood is open, and it will not arm. I believe that this has no other detrimental effects
 

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SupraNoob
Oct 13, 2013
105
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New Jersey
Dan_Gyoba;1970955 said:
Ground pin 4 on the starter relay.

http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=122

This grounds by default through the theft deterrent computer, As seen here: http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=038

Grounding that pin directly bypasses the theft deterrent computer and will allow normal starting regardless of what state the TDDS thinks the car is in. Alternately, you can pull the door panel and look for the switches which the key cylinders hit and trigger those, or probably simpler to send a ground pulse to pin 3 on the TDDS computer, which will make it think that the doors were properly unlocked with the key.

Edit: most people permanently disable the TDDS by grounding pin 1 from the TDDS computer. This makes the security system think that the hood is open, and it will not arm. I believe that this has no other detrimental effects

So that grounding pin is by the starter relay in the passenger kick panel?
 

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SupraNoob
Oct 13, 2013
105
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New Jersey
Looks like it may be something else or some loose circuit.

I went ahead and disconnected the "theft warning" box, cut the blue/orange wire, extended it with a 12 ga wire, put a ring terminal at the end and grounded it. Nothing... still no sounds or anything.

I went ahead and tested the starter with a temporary remote starter switch. One end of the wire went on the S terminal of the starter and the other on the positive on the battery. Pressed the button between the wires and woohoo the car turned on! I'm thinking about just making this button permanent instead of going through the entire wiring of the ignition switch to the starter -.-
 

Dan_Gyoba

Turbo Swapper
Aug 9, 2007
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The starter system isn't hard to diagnose.

You are getting power to the ignition switch if the car runs. You've just got to test that you're getting power from the key cylinder switch on the ST1 wire. (Test voltage drop under load versus the power feed to the ignition switch.)

Then test that you are getting power to the starter relay. Power from the ST1 goes to pins 1 and 2 of the starter relay. If you have a manual, it goes through the clutch safety switch, so test that if you have it. (Voltage drop across the switch.) Test that you get voltage on pin 4 of the starter relay, and check voltage drop against pin 2. If you have an automatic, you'll have the neutral safety switch to check.

Since you've already ruled out the starter by seeing that it works with voltage applied directly to the S terminal, the only thing left to do is see if you've got a broken wire somewhere.

For the TDDS wire that you cut/grounded... You DID make sure that it's the relay side that you grounded, and NOT the computer side, right? (Just gotta ask these things.)
 

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SupraNoob
Oct 13, 2013
105
0
0
New Jersey
Dan_Gyoba;1971438 said:
The starter system isn't hard to diagnose.

You are getting power to the ignition switch if the car runs. You've just got to test that you're getting power from the key cylinder switch on the ST1 wire. (Test voltage drop under load versus the power feed to the ignition switch.)

Then test that you are getting power to the starter relay. Power from the ST1 goes to pins 1 and 2 of the starter relay. If you have a manual, it goes through the clutch safety switch, so test that if you have it. (Voltage drop across the switch.) Test that you get voltage on pin 4 of the starter relay, and check voltage drop against pin 2. If you have an automatic, you'll have the neutral safety switch to check.

Since you've already ruled out the starter by seeing that it works with voltage applied directly to the S terminal, the only thing left to do is see if you've got a broken wire somewhere.

For the TDDS wire that you cut/grounded... You DID make sure that it's the relay side that you grounded, and NOT the computer side, right? (Just gotta ask these things.)

Thanks for all the infor Dan!

The side of the wire I grounded was the one coming down from the dashboard and not the one coming out of the theft computer.