hello,

I have an 86 trans am with a 350tpi setup and a 700r4 trans.

My torque converter never lock up.

If I turn the key. I have 12V on the A pin of the trans connector.

but if I try to send 12v on the A pin and ground on the B pin, no noise in the trans. I tried too to send 12v on the A pin and ground on the D pin, nothing too...

What do you think I should do to test...

thanks for your help

Marc

 

Solenoid or internal wiring to it would be suspect
If you are not seeing 12V on the tan/ black with 12V in on A then it is a internal problem ,have to drop the trans pan to investigate further

 

thanks for your answer.

I suspect my solenoid... but my transmission just has 2000miles, it is a summitracing 700r4.

Is the click of the solenoid really audible as I put 12V on the A pin and ground on the B pin ?

I ordered an ALDL cable to be able to check if my ecm send the information.

thanks for your help

Marc

 

Won't help
If you don't have 12V coming out then the ECM can do nothing

 

Ok, but how does it work.

There are 3 pins. A with 12V, B and D.

Which one send the information to the ECM for 3 or 4 gear.

Which one will have a ground for the solenoid ?

How can I test the solenoid (engine not running), due to the fact there is a pressure switch in the transmission ?

Thanks for your help

Marc

 

Hello,

I just checked, if I send 12V on the A pin (pink), I find nothing on the D pin ( tan /black), but I find 12V on the B pin (green).

I tried to send 12V on the A pin (pink) and ground on the B pin (green), maybe I had a small click once... not sure...

I tried to send 12V on the B pin (green) and ground on the A pin (pink)... I think it was a bad idea, I had a short circuit, my test cable didn't like !
After I retried to send 12V on A, and I still found 12V on B ! I retried to send 12V on A and grount B, and another short circuit...
I may have kill something !

thanks

Marc

 

Sure way to wreck something without knowing what a circuit does

Reading a circuit diagram helps.

Only wires you are interested in are the pink 12V supply and the tan / blk to the ECM where it grounds that wire to lock the convertor

Typical GM TCC circuit shown on right below

 

Hello,

reading your diagram... there is something I don't understand.
My car is parked, the tcc output from the ecm is the tan / black, if this switch closes grounding the tan /black, it seems normal to have nothing on the tan /black if I send 12V on A.

I can imagine, the B pin (green), is my pressure switch, this is the one I find 12V on it as I send 12V on A.

thanks for your help

Marc

 

The wire goes TO the ECM ; not from it

The tan / blk has to have voltage on it ( from going through the solenoid ) in order for the ECM to ground it and operate the lockup

 

ok, maybe there is an inversion on my transmission. It is not the original transmission of my car. It is a summit transmission.

On the factory wiring of the car, I have 3 wires. A : pink, +12V, B : green, D : tan / black.

If I send 12V on A on the trans, I find 12V on B (which corresponds to the green wire on the factory wiring). Maybe the B on the trans should correspond to the tan / black ? maybe an inversion ?

maybe are there several wirings on the connector of the trans ? and I have to invers 2 cables to make it compatble to my car ?

do you have a schematic which shows were each wire goes on the trans ?

thanks

Marc

 

For information, I have a torque converter with a "5" stamped on it.

It has a really high stall !

How can I check it is the good one with a lock up function ?

thanks

Marc