Torque Converter lockup switch

[Paddy McMahon]

Anyone have experience getting a manual lockup switch on the 48re to work with a pac brake? I discussed this with my mechanic and he thinks that the brake which wire taps in to the transmission already affects the torque converter and adding a manual switch to lock up the torque converter will create an open circuit or false ground and throw a code. He suggested that it may be possible to get the brake and a manual controlled switch on the torque converter to work together, but he had to figure out the wiring first before he spent my $ on it. Any ideas?

 

[cerberusiam]

A lockup switch is not going to do you much good with the EB as it won't allow a downshift. Since the 05's have no way to lockout OD unless you do the flash it is relatively useless. If you wire a 33 ohm 1/2 watt resistor between the ground and the switch the ECU won't throw codes. As long as it sees resistance in the 5-100 ohm range it is happy.



You really need a controller like BD and ATS market to controll the trans, TC, and EB effectively. Even then the 05's are a little goofy at times to get to work right. It can be done but just a little inconsistent at times.



Not sure what they are tapping the trans harness for unless they are looking for TC lock to activate. Does the Pac have a controller that is supposed to take of the shifting and lock?

 

[Paddy McMahon]

The Pac does have a wire tap in the harness that serves the transmission. It affects the lockup of the TC-without it the TC unlocks and the brake will not stay on. Mechanic was planning on DTT or ATS controller. I am trying to get the TC to lockup at very slow speeds to retard the truck going down steep hills in 4wd.

 

[cerberusiam]

The Pac does have a wire tap in the harness that serves the transmission. It affects the lockup of the TC-without it the TC unlocks and the brake will not stay on. Mechanic was planning on DTT or ATS controller. I am trying to get the TC to lockup at very slow speeds to retard the truck going down steep hills in 4wd.

Ahhh, the confusion clears. Without modifying the VB all you will get is 2nd gear lockup using the switch. That may or may not be slow enough for your needs.



Tap pin #7 on the trans control harness and run thru a switch with the resistor between switch and gound and it will work. It will only be effective in manual 2nd without some further mods.

 

[Paddy McMahon]

Thanks. Based on your comments I am SOL in trying to achieve a granny gear capable of holding back my truck in 4wd low range for crawling like I had with the manual trans in my first gen.

 

[cerberusiam]

Thanks. Based on your comments I am SOL in trying to achieve a granny gear capable of holding back my truck in 4wd low range for crawling like I had with the manual trans in my first gen.

Unless you modify the VB to lock in 1st gear, yep.



Still won't be the equivalent of the granny gear in a manual but in low range it would be pretty slow. You would want at least 1500-1600 rpms in the motor anyway to provide enough pressure to keep the TC locked tight. Try 4 lo manual 1st at about 1500 rpms and see if its too fast.

 

[Paddy McMahon]

This just gets me thinking about a swap to a 5sp or 6sp manual. Too bad the money tree and trade work are not in full bloom or I would actually consider it.