i just picked up this 94 lightning a few days ago. has 133,000 miles and runs and drives fine aside from needing radius arm bracket and bushings. i have noticed that it seems like it never locks the torque converter when driving. haven't driven anywhere but around town so havent really been over 45 with it. check engine light is off. any advice is appreciated thanks

 

Cycle the flasher button in and out a few times. Does the cruise control work?

 

yes the cruise does work. i did notice today that it does have a little bit of a rpm surge when cruising and could most likely use a tune up.

 

what all sensors control when the converter locks?

 

Nothing in particular. Speed sensor, TPS, when the computer decides to really. Those older EEC-IV computers were programmed to unlock the converter very readily for whatever reason.

While cruising, gently tap the brake with your left foot. If the revs suddenly jump, the converter just unlocked.

 

Applying the brakes or tuning on the harzards will keep the converter from locking up. Also, a failing converter may not lock up when commanded. However, this normally throws a code.

 

Limp mode also generally forces full line pressure - which you'd certainly feel.

 

If it were in limp mode it would have the CEL on wouldn't it?

 

Yes and the OD off light normally flashes. However, if the converter wont lock and there is no code,it's possible that the converter is bad: the clutch apply piston has failed. I would first find a way to verify if the ECU is commanding the clutch to lock before replacing the converter.

 

alright well i believe it is trying to lock because the rpms do rise a lil bit when i just barley touch the brake. so i am assuming it is just old and wore out that it really wont hold anymore... oh well. i do have an oil pan to put on it anyways so ill just search around for a new converter to put in when i get around to the pan. thanks for the help. all is appreciated