Torque converter lockup troubleshoot?

87we410877

Well-Known Member
Is there a torque converter lockup troubleshoot guide? I’ve done some reading and can’t find one. I see testing power at the brake pedal switch, jumping some pins out on the ALDL connector, etc. I first need to hear the solenoid working. How can I activate that? Doesn’t make sense to use the brake switch as the car needs 55 mph or something like that to activate.

Anyway, looking for a clear troubleshooting and diagnostic guide if you could.
 

mikestertwo

Well-Known Member
The TCC solenoid is powered through the brake switch when the brake is released. When the brake is applied the power is removed. This is a safety feature so the torque converter is not locked when the brakes are applied. Check for power on pin "F" of the ALDL. If there is no power check the adjustment on the brake switch. If you have power, jumper pin "A" to "F". That should activate the lockup solenoid. Pin "A" is ground. Is your problem you have no lockup or is it locked up all the time?
 

87we410877

Well-Known Member
The TCC solenoid is powered through the brake switch when the brake is released. When the brake is applied the power is removed. This is a safety feature so the torque converter is not locked when the brakes are applied. Check for power on pin "F" of the ALDL. If there is no power check the adjustment on the brake switch. If you have power, jumper pin "A" to "F". That should activate the lockup solenoid. Pin "A" is ground. Is your problem you have no lockup or is it locked up all the time?

Idk I think it’s fine I’m just not used to it. Power at the brake switch pink wires, power at pin a at the tranny when the switch is activated / deactivated and jumping pin a and f you can hear the solenoid. I guess I’m just being paranoid. Well. At least I know how to troubleshoot something else now lol
 

Fat Nat

Well-Known Member
Just drive 50 mph don't let off the gas and press the brake pedal in you should hear and feel the convertor unlock
 
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