(I also posted this to the trans board)...I am having some problems with my TC locking. I have a new trans and converter (trans is built with corvette components, and a corvette TC), and I love it... However, the TC has never locked on it. Yesterday, while driving around, I had my voltage regulator go out, and the voltage was around 17-18....and all of a sudden, the 7TC locks in 4th gear..... Now that the alternator is back to normal, the TC wont lock again. I have looked at the wiring schematics, and it seems that the computer does not activate the TCC with a ground, but sends it 12V.. is this right? I pulled the pan to look at the wiring to verify that the correct terminal was wired, and as with most aftermarket trans, the TCC solenoid is grounded to the casing, and the positive wire is activated by the computer. It would be logical that there is a relay somewhere in the circuit, but dang if I can find it.... I have tried the jumper wire method on the ALDL and using the A & F locations...but the wire just gets hot, and ends up causing a blown fuse. I have traced the wiring back from the trans connector, and all seems OK...

What are the additional parameters (stock) for TCC lockup (other than the physical ones like speed and what gear you are in)?

Thanks,


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Mike Metzler (Desert86Roc)
Mike@SpeedworldMotorplex.com
[*] Webmaster: SpeedWorldMotorplex.com[*] Click Here For My Racing Page[*]86 IROC 305 TPI (406 build in progress)
ET's @ 1250 ft[*] 14.28 @ 95.461 mph (uncorrected, NOS, no headers)[*] 15.365 @ 86.785 mph (uncorrected, Headers, no NOS)

 

I can't vouch for the parameters the ECM uses, but i can describe the TCC enable circuit.
12V is fed to the TCC solenoid through the brake switch. When you hit the brakes it disconnects power to the TCC.
Ground is fed to the solenoid by the ECM. ALDL terminal F is connected to this ground circuit.
This is how ALL GM TCC systems work that i have ever seen a wiring diagram for (including all thirdgen F-bodies, G bodies, and Sy/Tys). Look at your schematics again. If your tranny has either side of the TCC solenoind grounded to the case then it is wired wrong. As i illustrated, both power and ground are switched for the TCC.

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Ed Maher - Moderator @ The Carb Board
92 Z28 Convertible - Quasar blue / Tan top
LB9 4L60 GU2 G80 - stock, soon to be sleeper

- Definitely prototypes, high powered mutants of some kind. Too weird to live, too cool to die

 

Thanks Ed,.... I figured it out...the brake switch is bad. I was not getting 12v with the key on.... Most aftermarket trans eliminate the ECM activated ground, and put a 4th gear switch in... That means that in 4th gear, the TCC is locked, even at WOT, which is good for me and my highspeed cruising. The only disadvantage is when cruising in 4th at low speeds, you can bog. However, then you can just shift to 3rd.

Thanks.

 

Hey Desert86Roc or any one; on the aldl I know it's the supposed to be the top left and top right wire you use. But to make sure what are the wire colors that you hook to, to lock the converter up? I figure since you been messing with it you might rember off the top of your head.




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Getty up my *** this ain't no damn pony ride!!!!
86 IROC 383tpi
"bone stock"

 

I believe it is tan/black coming out of ALDL 'F'. You don't have to use the ALDL ground, chassis ground works just as well.
I know the color offhand cuz i just cut mine last night to hook a switch too. What's funny is, the damn thing ain't working, so i guess i need to do the same troubleshooting.lol.
...ed