Tallguy67

I have a sneaking suspicion that my T/C isn't locking up in 4th gear. I can feel it lockup in 3rd but I don't feel it in 4th and at highway speed in 4th gear I am hearing a funny sound that seems to be coming from the tranny. I hear the same sound when I am either holding steady speed or very light acceleration in 3rd gear before the T/C locks up. To be clear, I am not having T/C lock/unlock problems, that went away a year ago when I installed the noise isolator.

Would someone take a look at the diagram in the link below. Is there some way I could run a wire temporarily from the transmission relay (which contact?) to the inside of the truck and hook it to a light and ground the other side of the light? The goal would be to have the light come on when the T/C is supposed to be locked.

http://www.tstproducts.com/Torque%20...p%20Switch.pdf

Any thoughts? I really don't want to go down the road of installing a T/C lockup switch at this time, I merely want this for diagnostic purposes.

Ed ke6bnl

when my trans is locked up when I accelerate the rpm's gradually go up and when I let off the rpm's go down slowly, when not locked up the the rpms will increase fast then slowly go up and as soon as I take my foot off the gas they drop about 3gto400 rpm's instantly. but as to your question I bet we have wire guru that will make this any easy install.

drewk88

The Orange / Black wire, B11 is the Torque Converter Clutch Solenoid Control.

Looks like it goes low (to ground) when TC Clutch is locked, so connect one end of a 1K ohm series resistor to a switched +12 Volt source, the other end of the resistor to the LED anode, and the LED cathode to the B11 wire.