For those of you that have considered doing the tc lockup mod DON'T DO IT. I have just finished unwrapping half my wiring harness trying to find a short. The short started at the PDB at the fuse for the fuel pump and it was slowly draining my battery. It has been driving me crazy for months. Part of the TCLU mod you jump 2 pins where the TC relay go. The problem is the TC relay gets its power from the fuel pump fuse which cause you to ground out the fuel pump fuse. I am just glad I didn't unravel the rest of my wiring harness before I realized this. So for anybody that has done this mod and has had a problem with a slow drain on the battery that is where it most likely is.

 

good post. thanks.

 

Did you do the modtounlockthe TC with a switch and prevent it from locking until you flipped the switch back to normal?

 

no I did the mod to manualy lock the TC for when I was out wheelin I could lock it and help keep the heat down on the tranny. I haven't seen the mod to keep the TC from locking but I would love to see a write up on the mod

 

whats the tc lockup mod? what will it do for me?

 

https://dodgeforum.com/m_813840/tm.htm

To keep the tc from locking, youtake the same wire that you were grounding for the lock-up mod, and break it through a switch. With the switch closed the tc willfunction as it always does. With the switch open the tc will not lock-up

 

As requested, the picture shows my mod to the TC wiring. I used a DPDT switch. When the "A" contacts are open the "B" contacts are closed and visa versa. I cut the K54 OR/BLK wire near the PCM and soldered a pair of wires in series that I ran to the switch mounted under the dash on an custom L bracket. The arrow "to fuseblock" goes to the fuseblock in left end of dash behind the little popoff panel. I found a hot terminal there and ran a wire thru an inline 3 amp fuse to the switch.
So, during normal driving the B switch contacts are closed completing the original factory circuit. When I flip the switch the B contact opens therefore opening the TC circuit (preventing the TC from locking) and the A contact closes providing 12volts thru the resistor to the PCM C2/terminal 11.
Why did I need 12volts thru the resistor to the PCM? Ah well, that prevents the PCM from turning on the CEL. The PCM is "smart" enough to know the TC should be locked AND there should be current flowing thru the circuit to C2/11. So, the 12volts thru the resistor provides the necessary current tothe PCM that the TC circuit is ok.
If you click on the pic and your browser resizes it, move the mouse cursor over the pic until the zoom square appears, click it, then you can zoom in.
WARNING: Do not flip the switch to unlock the TC when it is locked. This circuit is to prevent the TC from locking. If you unlock the TC while it is locked you may blow outa component in the PCM. I let off the gas completely which always unlocks the TC and then I flip the switch.

[IMG]local://upfiles/58523/F71EB16BEBC44154B7F90CD7BAAF9A2D.jpg[/IMG]

 

ok i give up. why would i NOT want the tc to lock up ?

 

i got it from Bullydog and its great i get about 1-2 mpg better with my v8. my dads got the same thing on his diesel. idk about you guys but i think it works great!

 

hmm i think this would auchually work good for me till i get my new 4.10 gears right now with hwy driving at about 110 in od im just over idle at around 1400 rpm, and if i tirn od off im around 2500 rpm if i could have the tc stay unlocked in od that would bump my rpm up to around the 1600-1700 range in od that would dribe a hell of a lot better than down shifting at any bump in the road or truning od off all together....a question thow will it hurt anything driving with the tc unlocked at hwy speeds?