Engine/Transmission (1994 - 1998) TC lockup credentials

[KCloward]

Well I'm putting a lockup switch on my 95' 47RH but not sure of the credentials. I've got a three pole switch and a dual pole switch. The three pole has power, accessory, and ground terminals and on the dual I am guessing just power and ground. Which should I use? They are both on-off without the center option. Also what gauge wire? Also how should I run the cable? Would I cut a little of the rubber off of the blk/orange wire on pin54 in the ecm and solder the wire on then run to the switch, then drill a hole in frame bolt it and thereby grounding it or just use an existing bolt? I'm just opening up the world of diesels but have a fair amount of knowledge and being seventeen has also limited the options of knowledge but this site is amazing and your guys' help is well appreciated. Anyone that can help even just a little, please do.



thanks,

Bryce

 

[TGroves]

try tst's web site for the lock up switch ,,, http://www.tstproducts.com/Torque Converter Lockup Switch.pdf



as far as wire 18g will befine ,,, just tap in to it ,,,, switch i just used a two poll switch run one wire to the lock up wire #54 and on wire to a ground ie chassie or metal part of the dash would be fine,,,should be a grommet on the drivers side of the fire wall pull that out and just drill a hole in it ,if you are going to add more items to the truck ie gauges make sure to hole is big enought for future things

 

[Joe G.]

The way you wire is depends on what you want to do. If all you want is to force it to hold a lock then all you need is a single poll single throw toggle switch and the instructions on the TST web site. If you want the ability to force an unlock as well as a lock then you need a single pole double throw with center off toggle switch. Cut the wire from pin 34. Attach the part of the wire that goes to the transmission on the center terminal. Attach a ground to one outside terminal and the part of the wire that goes to pin 54 to the other outside terminal. You can ground it to anything in the truck that is grounded. No need to drill any new holes.

 

[Howard Durand]

It will not cost much more for the SPDT Center Off switch and it provides better control over the TC. There are times when the ability to unlock the TC is valuable. You may not be able to find the switch you need at Radio Shack. If not, go to Mouser Electronics (mouser.com) and you can find about anything you want. Get one with a large enough toggle so you can find it in a panic.

 

[Vaughn MacKenzie]

I'm wanting to install a lockup switch on my '98, but I would like to instead install a relay on the ground line which could be controlled by a signal that tells the TC to unlock when certain conditions are met, ie when you get below a certain speed or the PCM calls for a downshift. That way you could leave the switch in "lock" mode and yet have it unlock when you slow down or when you suddenly have to tromp the Go pedal and want it to downshift. Basically I'd want it to just signal the relay long enough for the TC to unlock, then ground it again so that when you speed up again it'll relock on its own. I guess this would be a crude smart controller of sorts but it would take some planning to set it up right and get it to operate as you'd like, if that's even possible.



Vaughn

 

[Joe G.]

I'm planning on something like that eventually. Big honey do list to finish first. I plan to monitor EGT as Howard does. I also plan to have a MPH input and (maybe) an RPM input. It will drop out of OD and/or unlock if EGT gets too high. It will also have a minimum MPH threshold (adjustable) that will cause an unlock if MPH drops below that. Other goodies may be included depending on if it includes an RPM input. I think I can buy a controller to do something like this for MPH, but I get more satisfaction from building one that will work just like I want.

 

[KCloward]

Thanks a lot guys. I got off work to late so the auto parts and radio shack are closed but after tomorrow (hoping we pour early) I should be able to do it and then me and my dad can throw it in. That mph and rpm would be an awesome little add on. . which reminds me I need to get my tach fixed...

 

[Howard Durand]

Vaughn,



The scheme I am using now does pretty much what you are talking about.

I have the original Mystery Switch setup located in the ash tray but don't use it much anymore.

I have an electronic speed alarm circuit that I had to buy already made up. I use it to operate a relay that is in the TC control circuit. It keeps the TC from operating until the vehicle reaches a set speed then closes, allowing TC to lockup normally.

It could just as easily be used to force TC lockup but I have not found that to be necessary.



I also have anotlher circuit that I made up myself that monitors EGT and lights an LED at a preset temperature of 1100*. If EGT continues to rise it will force a shift out of OD at 1250*



Joe G sent me some information on a solid state frequency to voltage converter chip that can be used to do the same thing as the little $100 speedometer circuit that I had to buy.

Joe knows his electronics, especially solid state digital electronics, much better than me.

I am somewhat of an analog person and really not too sharp on that but I am going to try to do something with the frequency to voltage converter chip. I am sure it can be used to replace the speedometer circuit that I bought.



Howard

 

[KCloward]

I'm pretty happy right now. Everything went down real good and the TC lockups and the power that is their brings a smile to my face... I can't wait till the 370s.



Bryce

 

[Vaughn MacKenzie]

Howard I think I've seen you post about TC lockup control before. My main issues with the stock TC lockup operation is it unlocks when I get to about 3/4 throttle in 3rd gear (which is easy to do when you're totally stock other than 300 injectors). It was a real PITA when pulling the camper trying to accelerate up a hill onto the freeway. I really needed it to stay locked at WOT. Also when I hit the OD button to turn it on or off it takes too long to lock up again, even though the conditions are right for lockup.

 

[Joe G.]

Vaughn,



There is a thread about the TPS by ridesamule and Howard that explains how to replace the TPS with a pot. That will stop the behavior you have a problem with. It's pretty simple and easy to use. I don't have it bookmarked so you will need to search for it in this forum.

 

[Vaughn MacKenzie]

Yeah I saw that before Joe, wasn't that interested in replacing the TPS with a pot. Might try it someday though.

 

[Blue Coyote]

Howard I think I've seen you post about TC lockup control before. My main issues with the stock TC lockup operation is it unlocks when I get to about 3/4 throttle in 3rd gear (which is easy to do when you're totally stock other than 300 injectors). It was a real PITA when pulling the camper trying to accelerate up a hill onto the freeway. I really needed it to stay locked at WOT. Also when I hit the OD button to turn it on or off it takes too long to lock up again, even though the conditions are right for lockup.

My 97 had the same issue (no fun when towing a 38' GN or when driving in So Cal traffic) until I did the Howard / Ridesamule TPS conversion. Disconnected the TPS and added a potentiometer on the dash. Has worked GREAT for several months and many tows. Very simple to do, only took about 30 minutes to build and hook up.

 

[Howard Durand]

Vaughn, I just completed a round trip to Nebraska and back and am thoroughly satisfied with the TPS removed and a potentiometer in it's place. There is no kickdown from TC lockup. Neither will it unlock under heavy throttle.

It will disengage when engine RPM drops below 1200 and can be manually disengaged by tapping the brake pedal. Also by the use of a switch or, in my case, a dimmer switch on the floor.

Usilng the potentiometer does not prevent the TC from locking up too soon though, so

I also use a speedometer circuit to control TC lockup.

The potentiometer setting I am using for towing allows OD to engage at 45 mph and the speedometer circuit holds out the TC until the vehicle reaches 55 mph. This has worked very well and I no longer have the lugging and shuddering problem when TC locks almost immediately following OD engagement.