A-Body lockup converter question

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Apr 20, 2016 | 09:37 AM

kainedogg

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A-Body lockup converter question

For those with the GM A-Body's and 4l60e's how are you locking and unlocking the torque converter? I have a custom wiring harness and the car is fuel injected.
I read where you could run a late model brake switch and one of the wires goes to the ecm. That was years ago and my project is now closer to fruition.

Apr 20, 2016 | 12:56 PM

98 Silver SS

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Just like you thought. Install the brake switch and let the ecm handle it.

Apr 20, 2016 | 01:07 PM

1964SS

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It is as you expected. You need to swap out your brake switch for a late model switch with dual switches. For the TCC you will run 12v ignition feed to the switch and then connect the other end to the appropriate pin on your PCM. If you have the red blue 411 pcm it's pin 33 on the C1 blue connector.

Apr 20, 2016 | 09:28 PM

kainedogg

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Thank you gentlemen.

Apr 20, 2016 | 09:33 PM

lizeec

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This is the switch you need
AC DELCO D850A
G.M. #25524845

Apr 21, 2016 | 09:48 AM

04Z06vette

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wish I saw this sooner. I used a relay to change the 12v with brakes on signal from brake switch to the 12v when brakes are not applied needed for the PCM. this would have been cleaner.