Please Help somethings wrong with my tranny

[hgriz]

I had another post about this but noone seems to be taking a look, this one just sums it all up.

My torque converter is locking up in all gears including first through third. This makes for extremely hard shifts as well as a realy rough ride below 20mph. If I unplug the tranny wiring harness the problem goes away but of course the torque converter no longer locks up. I replaced the TCC solenoid that wasn't the problem. I also used a test light to check voltage to the tranny wiring harness A and D (the upper and lower wire to the front of the car) have voltage, B and C (upper and lower rear) do not. I also used this to test the brake switch and it is working properly. Where do I go from here? Please help this is an extremly irritating problem and it cannot be good for my tranny.

 

[MeanBuicks]

If unplugging the connector prevents the converter from locking, then the problem is electrical, not mechanical.

You tested your brake switch and verified that you have 12V at terminal A. Good.

Now, for some reason, the solenoid seems to be energizing which means that it has a ground somewhere. I would suggest taking your multimeter and testing continuity between terminal D on your transmission connector and the transmission case. That'll tell you if your solenoid negative lead has been pinched or chafed inside the pan, shorting it to ground.

Good Luck!

 

[hgriz]

Okay but thats a slight problem since I don't have a multimeter right now (mine broke), of course when I have the money I'll buy another. However, I don't understand how changing the TCC solenoid would not have fixed this because when you replace it the whole internal wiring harness is replaced as well. I had the same problem before replacing the TCC it should have been fixed by replacing it if an internal short was the problem, right? Or am I missing something?

What about wiring inside the car? Does any of it go inside? If so where could I look for a short.

Anyway thanks for the reply Greg.

 

[MeanBuicks]

Oh yeah. I forgot that you had stated that your meter broke in an earlier thread. Hmmm.

Yes, it is possible that the transmission portion of the vehicle harness has a short to ground as well. It runs from the transmission, up into the main harness in the engine compartment. As far as diagnosing it without a multimeter; that won't be fun.

 

[alb84]

It is not that big a problem. Just wire a switch into either side or either wire on the beack switch. lock it up whenever you want. gotta go . Later....Danny

 

[hgriz]

Originally posted by alb84
It is not that big a problem. Just wire a switch into either side or either wire on the beack switch. lock it up whenever you want. gotta go . Later....Danny

So are you saying to cut the wire and make it manual control only? Which wire is the one for the brake switch? I guess its under the dash going to terminal F on the ALDL? Will this keep it from locking up?

 

[hgriz]

I bought a cheap multimeter and tested continuity between the wiring harness and the tranny case all wires show continuity with case. I unplugged the wiring harness and tested the connector in the tranny, and only the two rear wires showed continuity, so my short is not inside the tranny but outside it, right? Where do these wires connect with the main harness. I could not see.

 

[MeanBuicks]

There should be continuity between terminal C and the pan as that goes to a normally closed pressure switch. Continuity between D and the pan isn't good and is probably why your TCC is always on. It's got a constant supply of 12V & ground.

Your new harness may have been pinched by something. I can think of one additional test utilizing your newly aquired meter.

Put it in the current measurement mode. With the vehicle harness unplugged from the transmission, put the meter between the 12V supply (terminal A) from your harness to the terminal A in your case connector.

Turn your ignition on, engine off. If your meter registers a current draw, the solenoid is grounding inside the pan. If you are not seeing any current flowing, which a normal system should not, then I'm confused too.

 

[hgriz]

Well I guess were both confused then because I saw 0.0 amps ( a is the top towards the front of the car right). Will adding a toggle switch to the brake switch allow me to turn the lock up off as well as on? alb84 said to add one but I thought this only allowed you to engage the converter not unlock it. If it allows you to unlock it I think I'll just add the switch for now, that is unless anyone has some suggestions as to what to do.

 

[alb84]

I am sorry, I had an interuption while writeing the last post. There is a problem somewhere in the lock up circuit. The other people replying to you are working to fix your problem, not patch it. The best thing to do is find the problem, fix it , and then decide if you want a switch to manually lock or unlock your converter. You had said that the brake switch was working. So I took that to mean that when you are locked up and tap the break it unlocks the converter. The theory then that you could put a switch in that portion of the circuit is basically sound, but we have not adressed what is really wrong. Here are a few ifs to consider before cutting into that wire. If you have to drive the car, and If you beleive its going to break something to keep driving it that way, and if (like me) you don't have an extra minute in the day or an extra dollar to have someone else take a look at it. Then cutting a switch into that circuit is an option that could make the car usable until the real problem can be adressed. I did'nt mean for the switch to be a permanent cure. I know I have a copy of that circuit around here somewhere, If I can find it I will scan it in for you. Later.....Danny

 

[hgriz]

Okay thanks Danny. I think I am going to add the switch because I don't know where to go from here. It seems I am stuck. Hopefully I can eventualy find the problem but untill then the switch will work for me.

 

[hgriz]

Thanks for your help

Okay I added the switch and hurray it works (its rigged up but oh well). So I'm going to put it on the backburner for a while till classes get out in a few weeks ( and my student loan gets here) and I have the time and money to mess with it. So thanks to everyone for your help.