zachu812
New member
- Joined
- Apr 20, 2016
- Messages
- 419
Ever since I installed the 6x.013s in my truck I've had an issue with the truck shaking in OD under light throttle at speeds below ~55 mph. Also, anything more than light acceleration would result in a cloud of smoke every time the truck would lockup in 3rd gear and again going into OD. My drive to work is mainly 45 mph so I kept OD off which got rid of the shuddering but I was revving the engine higher than I needed to so I figured out a way to stop it.
Using a 3 position switch I wired up a little circuit that would allow me to choose: 1. TCC locked, 2. PCM controls TCC like normal, or 3. TCC unlocked. Now I can leave the TCC unlocked on my half hour commute so the revs stay much lower which means I don't have to listen to the engine screaming at me on early mornings and the trans temps stayed close to where there were before.
Parts List:
1. SP3T switch #M2024SS1W01
1. 5V 1A regulator #LM7805CT
2. 1/4W 33 ohm resistors #MF1/4LCT52R330J (or any other quarter watt 33 ohm resistor)
2. 50V 10uF capacitors #ECA-1HM100I (or any other 50V 10uF capacitors)
Description: Along with the parts listed above you'll need various other stuff like electrical tape, solder, wire and etc. The wire under the hood you need to tap into is the TCC solenoid control wire that is located at B11 in the middle of three plugs going into the PCM on the passenger side firewall. The wire is orange with a black stripe, if you already have a lockup switch you can simply cut the orange/black striped wire where that was tapped in and attach a length of wire to each of the cut ends and run it into the cab. From there you will take the wires that you just ran into the cab and choose the one that leads to the PCM, now you can solder it to the two middle terminals of the switch. Take the other of the two wires that you ran into the cab (it should be running to the TCC in the transmission) and solder it to the switch as shown in the picture.
The 7805 voltage regulator converts a keyed 12 volt source to 5 volts and runs it to the PCM through a 33 ohm resistor to trick it into thinking the TCC is still connected when you have the switch in the unlocked position. I'd recommend making the regulator circuit as a part of a little circuit board or solder the leads and tape it up to protect everything. You will only have three wires coming from here if you do it right (all the grounds can be connected together). I ran the 12V keyed source wire to the #9 fuse on the side of the dash, the ground will attach to any good chassis ground of course, and the other wire will connect to the switch through a 33 ohm resistor as shown. The last terminal of the switch is not needed so it's left empty.
I'd suggest putting the whole circuit and switch together on a bench and testing it with a multimeter before taping it all up, when done correctly you'll only have 4 wires to connect once you're at the truck. Unfortunately I didn't take any pictures during the assembly and install process.
For those who don't already know a lockup switch can be hard on the input shaft, and leaving the torque converter unlocked under heavy load for a long time can cause trans temps to get out of control. I take no responsibility for damages done by using any of the information in this writeup. When used improperly it's possible to damage your transmission, but when used properly it will improve the driveability of the truck.
If you have any questions shoot me a PM, I'll be happy to help where I can. I need do a better job on the wiring diagram, but it's late and I didn't want to keep putting this off, I think this should suffice for most. Also, the switch I ordered is a little smaller than expected. It worked out great for me since I wanted it to be small and out of the way, some of you might find it to be too small and possibly fragile. Any SP3T switch can but used but it must be an ON-ON-ON switch for this to work properly, as of now the only one I can say that will work for sure is the part number that I provided.
Wiring schematic
My switch placement
RPM's at 40 mph in OD with the TCC unlocked, no shuddering at all
Trans temps after my drive into work, only ~5 degrees higher than before
Using a 3 position switch I wired up a little circuit that would allow me to choose: 1. TCC locked, 2. PCM controls TCC like normal, or 3. TCC unlocked. Now I can leave the TCC unlocked on my half hour commute so the revs stay much lower which means I don't have to listen to the engine screaming at me on early mornings and the trans temps stayed close to where there were before.
Parts List:
1. SP3T switch #M2024SS1W01
1. 5V 1A regulator #LM7805CT
2. 1/4W 33 ohm resistors #MF1/4LCT52R330J (or any other quarter watt 33 ohm resistor)
2. 50V 10uF capacitors #ECA-1HM100I (or any other 50V 10uF capacitors)
Description: Along with the parts listed above you'll need various other stuff like electrical tape, solder, wire and etc. The wire under the hood you need to tap into is the TCC solenoid control wire that is located at B11 in the middle of three plugs going into the PCM on the passenger side firewall. The wire is orange with a black stripe, if you already have a lockup switch you can simply cut the orange/black striped wire where that was tapped in and attach a length of wire to each of the cut ends and run it into the cab. From there you will take the wires that you just ran into the cab and choose the one that leads to the PCM, now you can solder it to the two middle terminals of the switch. Take the other of the two wires that you ran into the cab (it should be running to the TCC in the transmission) and solder it to the switch as shown in the picture.
The 7805 voltage regulator converts a keyed 12 volt source to 5 volts and runs it to the PCM through a 33 ohm resistor to trick it into thinking the TCC is still connected when you have the switch in the unlocked position. I'd recommend making the regulator circuit as a part of a little circuit board or solder the leads and tape it up to protect everything. You will only have three wires coming from here if you do it right (all the grounds can be connected together). I ran the 12V keyed source wire to the #9 fuse on the side of the dash, the ground will attach to any good chassis ground of course, and the other wire will connect to the switch through a 33 ohm resistor as shown. The last terminal of the switch is not needed so it's left empty.
I'd suggest putting the whole circuit and switch together on a bench and testing it with a multimeter before taping it all up, when done correctly you'll only have 4 wires to connect once you're at the truck. Unfortunately I didn't take any pictures during the assembly and install process.
For those who don't already know a lockup switch can be hard on the input shaft, and leaving the torque converter unlocked under heavy load for a long time can cause trans temps to get out of control. I take no responsibility for damages done by using any of the information in this writeup. When used improperly it's possible to damage your transmission, but when used properly it will improve the driveability of the truck.
If you have any questions shoot me a PM, I'll be happy to help where I can. I need do a better job on the wiring diagram, but it's late and I didn't want to keep putting this off, I think this should suffice for most. Also, the switch I ordered is a little smaller than expected. It worked out great for me since I wanted it to be small and out of the way, some of you might find it to be too small and possibly fragile. Any SP3T switch can but used but it must be an ON-ON-ON switch for this to work properly, as of now the only one I can say that will work for sure is the part number that I provided.
Wiring schematic
My switch placement
RPM's at 40 mph in OD with the TCC unlocked, no shuddering at all
Trans temps after my drive into work, only ~5 degrees higher than before
