Can any body tell me where the wire for the lock up comes from. Does it come from the harness in the engine bay or some where else ? I see the plug on the trans ( drivers side ) but can't tell where it is feed from. I want to delete the ecm from the motor, can I do this without screwing up the trans. This is a new trans with a lock up converter.
Thanks

 

This comes up about every other week, why do we have no sticky about it?
Since I don't feel like typing a book, either do a lot of online research, or just order one of the aftermarket lockup kits. I've used the Painless kit, and I liked it, but since then I learned to do the same thing for free.

 

In your case you can pretty much ignore the factory wiring, all you need is the plug to the trans and a pigtail long enough to attach to. If I remember correctly it comes off the harness going into the passenger side fender. There are 3 wires, purple (12V supply), green (ECM reference), and tan (ground).

You can either buy a lockup kit;

(http://www.summitracing.com/search/p...tOrder=Default)

Or, you can wire in a switch as I have done for substantially less expensive. The TCC is engaged by allowing the circuit path to ground the lockup solenoid in the trans, which re-ports the fluid to allow lockup. Usually the computer supplies this ground signal, but the same can be done with a switch for manual control. I created a circuit in my car that allows either normal operation (automatic lockup in 4th gear), or lockup in 2, 3, or 4th gears when the switch is activated. 1st gear in the 700R4 is mechanically unable to lockup. The circuit normally goes to the trans through the plug, then to the solenoid, then depending on the version of 700R4 you have either grounds to the case or continues through a temperature switch in the valve body, and then grounds to the case. Both the TCC solenoid and the temp switches are prone to failure, and either can cause loss of lockup. Thankfully they are also cheap and easy to replace. Either route you go you will have to drain and drop your trans pan to install. It's also a good time to install a trans pan drain plug, O'Reilly Auto Parts has them in stock for less than $10. My car has lockup control in 2, 3, and 4th, but my temp switch has gone bad preventing automatic operation. I have a thread on here showing the circuit I created, if you search my threads you will find it. I have not gotten to LEDs to work, as they need a separate power source and I have not attempted re-wiring yet (they cause too much voltage drop in the current configuration). I can verify that my trans locks and unlocks when the switch is activated however. There is also a vacuum switch that detects when the engine is under heavy load (heavy acceleration) to disengage the TCC. The TCC is also disengaged when brakes are applied by running through the already-present brake switch. The circuit cost me $5 for the switch, $5 for the vacuum switch, and maybe $15 worth of 12 gauge wire and connectors to create.

https://www.thirdgen.org/forums/tran...cc-lockup.html

The last diagram is the setup I currently have. It has made a difference on both mileage and fluid temps (and therefore coolant temp). I also recommend an auxiliary trans cooler, as heat is the biggest killer of an automatic transmission.

 

Thank you very much for the info. I bought a painless lockup harness as well as a harness for the fuel pump. I bought an 87 Iroc roller and installed my drive train, but did not consider the ecm when I did this. At 60 yrs old I am still learning everyday. With the above harnesses I should be good to go. Again, thank you for your patience in explaing this to me.

 

It's in the Carb section for some reason, guess the sticky should be in both..

https://www.thirdgen.org/forums/carb...c-control.html

 

That is a very informative sticky. Just got done installing the Painless TCC kit, can't test drive yet. About a weeks worth of work before I will have it road ready.
Thanks for the info.