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TC switch howto (with pics)

52203 Views 9 Replies 6 Participants Last post by  Ruben121
Just documenting the TC lockup switch with pictures. I've had a PM requesting info on it and the poor mans propane setup.

Middle harness. Orange wire w/black tracer (might be a navy blue).

The following information is supplied at no cost or obligation. Note that use of this method of lockup may be hard on vehicle drivetrain and may void vehicle drivetrain warranty. Use makes vehicle drive like a manual transmission in 4th gear such that vehicle may/will stall at low speeds/stops if lockup is not disconnected.

Note: Some 1996 automatics require computer to be reflashed by dealer for the lockup switch to work.
Step-by-step Instructions:

1. Install jumper wire in place of the trans relay in the Power Distribution Center (black box behind driver side battery) as shown in diagram below. This jumper wire will supply 12 volt positive to the transmission torque converter clutch solenoid. This jumper will be electrically hot thus it should be installed so as not to short against ground. I used two scraps of metal brackets to make prongs. You can get taps that will insert into the slots from any parts store. It was only what I happened to have at the moment.



Note: The position of this relay changes from one year to the next. Consult relay location chart on inside of relay box cover.


2. Install ground wire from the B11 orange wire with black stripe to a switch or relay such that the ground source can be turned on and off. The B11 wire is located in the middle computer connector located on the firewall behind the air cleaner.



3. Install the switch wherever you like. I installed mine to the left of the column. It's the black switch. The smaller switch is for my XTZ+.




4. Ground the wire. I used this screw under the dash.



5. Enjoy!



Note:You can use a double pole double throw relay from radio shack to automatically disengage the TC when the brakes are applied. I've got the relay, but haven't installed it yet on my truck. Here's a crude diagram of how it would be wired up.



The relay I bought from radio shack is
RadioShack.com - Cables, Parts & Connectors: Component parts: Relays & transformers: 12VDC/3A DPDT Plug-In Relay & Socket



I don't use mine except when I'm up to speed on the highways. I use it to counteract the annoying locking and unlocking that happens from the computer getting line noise. Hope this helps.
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Good write up. You can buy (5 for a buck, I think) 33 ohm resistors @ Radio Shack and put that in the ground line from the switch. You can leave the relay in and not set codes or have the tranny go into limp mode. Personally, I would not want my TC to unlock when I put on the brakes because you would lose the increase in compression braking that comes with having the switch engaged. I absolutely hated that from the first time I drove this rig.

I have also started hitting the switch the minute I start moving. It locks and causes the trans to stack the shifts into third. I hit third about 20 MPH and it seems to have increased my in town mileage about a mile to the gallon.
 
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just made the install the wiring is rough but that can be fixed. wired it to a foot dimmer switch will take photos later oh ps it works good
 

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Discussion Starter · #4 ·
Good write up. You can buy (5 for a buck, I think) 33 ohm resistors @ Radio Shack and put that in the ground line from the switch. You can leave the relay in and not set codes or have the tranny go into limp mode. Personally, I would not want my TC to unlock when I put on the brakes because you would lose the increase in compression braking that comes with having the switch engaged. I absolutely hated that from the first time I drove this rig.

I have also started hitting the switch the minute I start moving. It locks and causes the trans to stack the shifts into third. I hit third about 20 MPH and it seems to have increased my in town mileage about a mile to the gallon.
Just be careful. Locked shifts aren't nice on stock transmission shafts. :thumbsup
 

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Just be careful. Locked shifts aren't nice on stock transmission shafts. :thumbsup
I have been doing it for months with no issues. If you look at Dunrite's ads Tony advertises his VB as being capable of locked shifts.
 
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I have been doing it for months with no issues. If you look at Dunrite's ads Tony advertises his VB as being capable of locked shifts.
Yes, the VB might be able to handle locked shifts, but the input shafts weren't designed for it. Just do a search on input shafts to see some of the carnage.

Romping on it is what would lead to the issues of breaking. If you're not hard on it, it's likely you'll not have a problem.

I just want to state, I'm not responsible if anyone breaks their input shaft from misuse.
 

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guess i should have mentioned that i have a built tranny but this thing makes my truck sound like a 3rd gen when im at low speeds. pretty neat bomb
 

· Go for Broke
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good job...it's now a sticky and moved to the tech section :thumbsup
 

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The only way i fixed mine. I purchased a new apps from dealer no help, finally decided to try a Chinese switch on eBay, was amazed, 12,000 miles later, no issues.. i have 2 others for back up. cost like $10.95 each. issue solved..i have all the other so called fixes with no help from them...
 

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I have this done to my truck , I did break my input shaft but I upgraded to a billet one piece shaft and I haven't had no issues since. oh and it made my truck run so much faster when I'm playing with it . I know it cant be healthy in the long run .
 
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