I installed a lock up switch the other day but it doesn't seem to be working right. I can sometimes hear it (via engine rpms) lock up rolling at an idle, but I can't ever get it to hold lockup. I can slow down to a stop with my lockup switch on. If I am running 70 down the road with it on and I slow down it well stay engaged until engine hits about 700-1000 rpms then unlocks. What is wrong? Do I not have a good enough ground, or heavy enough gage wire. I used 16 gage wire. Any help?
Heath

 

Oh it was on my 94
Heath

 

just a guess, but it's slipping, and not actually unlocking...

 

I have done a bunch of these, it sounds like you have something wrong. Wire size is not critical, you are controlling relays(very low amperage draw). submit a drawing of how you have it wired.

 

Stock converter? There are several things that can contribute to lockup slippage. If it is the original stocker then that means it is cooked.

Give some more details about the 94 - any engine mods?

 

As well as the TC slipping, you might have a slip in the front clutches?

 

I ran a wire off of pin 54 behind the air filter on the firewall, I belive orange and black, though a toggle to a ground. It is supposed to be on its second tranny, I just rolled over 200k the other day, don't know when the tranny was redone. I am hoping to put a goearnd brothers tranny in next spring, do you think it well last that long, is there something cheap and easy I can do to limp it along until then, like a valve body, or maybe like the amsoil torque dive fuild, it is suppose to be supper sticky, made for heavy duty autos like in dump trucks, garbage trucks, and fire trucks. No major engine mods yet well come in spring also. I know the pump has been turned up, the tamper proof screws are not tamper proof anymore and I was thinking of advancing the timing a bit this weekend. The tranny itself feels soild when it shifts, but sometimes it forgets to shift and you have to back out of it a little. How does that work anyway, with the tc locked up it well upshift but not downshift right? anyway that was what I was told. I apoligize I don't know squat about autos. Thanks
Heath

 

I have a '97 that a mystery switch won't lock the T/C on. My Friend has a '97 and his dad's '01 that the switches work on, But we've tried them on mine, another '97,a '98.5 24v and a '99. Any ideas why it won't lock up on 4 of the 6 trucks. There all 4x4 if that matters. Thanks

Brett

 

It should work on any of the pre 1998.5 trucks, on the post 1998.5 trucks it will throw a code. You can remove your valve body, up the line pressure a bit and increase the size of the hole that supplies oil to the TC lockup clutch and get by for a while.

 

I think the lock up is slipping. Get that TPS checked out as this can also affect lockup line pressure if the voltage is not high enough. For the 3-4 shift, again the TPS is largely responsible for that shift timing. Do a TPS search and you will get all the info you need to check, adjust and repair the TPS. 1-2 and 2-3 are your TV cable adjustment. The key here is that you want to run somewhat higher line pressures than stock to give the lockup as much pressure as REASONABLY possible. A good shift kit installed by a Knowledgable tranny tech can help alot but not much if the current clutch is fried. This also does what Mc suggested: more lockup flow which engages faster with less slippage to prolong it's life.

You are correct stating that the tranny will not unlock or downshift under any condition as long as the switch is on.

 

The lockup switch works on my 94. I dont think your converter is slipping that bad. If you let it lock up in overdrive by itself can u feel it, and step down on it some, and tell that its locked? Also, once the tranny hits 4th gear it wont downgear. If im running along in 3rd gear with my TC locked up, and at low rpm's/mph, i can put it to the floor, and it will downgear to 2nd, and gain speed hard, then hit 3rd gear. I bet you probably dont have a good ground, or it could be the wrong wire you got. There is another one that looks a lot like it if im not mistaken. In my eyes, if your converter was slipping so bad that you could stop with it locked, your tranny would be gone anyway. You dont have something hooked up right. Have you had any luck with it yet?

Eric