Engine/Transmission (1994 - 1998) Mystery switch stopped working

[55gene]

Has anybody had this happen to them; I had my 95 47rh rebuilt with an upgraded TC and VB now my mystery switch stopped working. The TC will lockup but the switch will not hold it in lockup like it did before I had the work done. Still have problems with the TC lockup fluctuating in & out at highway speeds. The transmission shop said to run it for some miles with the alternator disconnected to clear up the TC lockup fluctuation problem. The transmission shop did put another new TC lockup switch in the VB but problem is still there... non working mystery switch!

Would ATF in the VB connection plug cause problems?

Moving pretty soon and need the truck to be working right!

There will be a reward for the input that fixes it!

Help!

 

[LandShark]

Your problem is not with the mystery switch. You state " Still have problems with the TC lockup fluctuating in & out at highway speeds". This and the fact that the problem started after the rebuild makes me thing the problem is in the transmission.

You may want to find a more competent trans guy. There is no way that driving with the alternator disconnected will "clear up the TC lockup fluctuation problem".

The trans temp sensor circuit can cause the TC to unlock. You could try to unplug it and put a 1000 ohm resistor across the plug to fool the PCM.

Are you seeing other problems when the TC unlocks? If the engine speed sensor is going bad it can cause the TC to unlock, along with causing the tach, AC, and cruise control to drop out.

 

[55gene]

Thanks for the input LandShark. I will try the suggestions. Also thinking about swapping out the VB to see if the problem is in there.

Thanks, Gene