What signals should I have at the Trans plug?

[TURBOPOWERED68]

Going into the Trans what signal should be at the plug.

Example:
if i unplug the Trans and check the top left wire on the plug, (harness side)(plug facing me) what should the signal be? +/- nothing
And the same for the rest of the wires.

also if the trans is in gear (and pluged in)what signal should be cominig out of the Trans when?

[TURBOPOWERED68]

Ttt

[SRGN]

Going by wire color, tan/black is lockup(pin D), purple is +12V feed(pin A), dk grn/white is 3rd gear switch(pin C), light blue is 4th gear switch(pin B).

[TURBOPOWERED68]

Originally Posted by SRGN

Going by wire color, tan/black is lockup(pin D), purple is +12V feed(pin A), dk grn/white is 3rd gear switch(pin C), light blue is 4th gear switch(pin B).

SRGN thanks for all of the help Dude.

Is this how it works?
1- The computer feeds tan/black -/ground to activate the L/U
2- Purple is always live +12V to the L/U solenoid
3- 3rd gear switch Dk grn/white feeds the computer Ground when the Trans is in 3rd gear.
4-4th gear switch Lt blue feeds the computer Ground when the Trans is in 4th gear.

Did I get this right?


Does the computer know when the car is in 1st or 2nd?
If so
How?

[SRGN]

That's pretty much it, ECM uses the park/neutral switch to know it's in gear and if the 3rd or 4th gear switches aren't activated it assumes 1st or 2nd gear(doesn't make a difference to ECM whether 1st or 2nd).

[TURBOPOWERED68]

Originally Posted by SRGN

That's pretty much it, ECM uses the park/neutral switch to know it's in gear and if the 3rd or 4th gear switches aren't activated it assumes 1st or 2nd gear(doesn't make a difference to ECM whether 1st or 2nd).

thanks Dude.

[YGETV8]

Originally Posted by TURBOPOWERED68

SRGN thanks for all of the help Dude.

Is this how it works?
1- The computer feeds tan/black -/ground to activate the L/U
2- Purple is always live +12V to the L/U solenoid
3- 3rd gear switch Dk grn/white feeds the computer Ground when the Trans is in 3rd gear.
4-4th gear switch Lt blue feeds the computer Ground when the Trans is in 4th gear.

Did I get this right?


Does the computer know when the car is in 1st or 2nd?
If so
How?

Given this information, can I temporarily tee into the ground wire at the harness with a toggle wired in the cabin and manually override/test my converter lockup?

Thanks, Jay

[SRGN]

Originally Posted by YGETV8

Given this information, can I temporarily tee into the ground wire at the harness with a toggle wired in the cabin and manually override/test my converter lockup?

Thanks, Jay

Just ground pin "F" of the ALDL connector under the dash and it will accomplish the same thing. Pin "A" is ground, you could do it with a paper clip if you wanted to.

[YGETV8]

Thanks, but I forgot to mention that I have no ALDL - it wasn't installed during the conversion. I would like to do it at the trans and make sure the problem is in the wiring before that, not in the trans itself.

[TURBOPOWERED68]

"ECM uses the park/neutral switch to know it's in gear"

i could wire in a switch but to which wires?

[TurboDave]

Originally Posted by TURBOPOWERED68

SRGN thanks for all of the help Dude.

Is this how it works?
1- The computer feeds tan/black -/ground to activate the L/U
2- Purple is always live +12V to the L/U solenoid
3- 3rd gear switch Dk grn/white feeds the computer Ground when the Trans is in 3rd gear.
4-4th gear switch Lt blue feeds the computer Ground when the Trans is in 4th gear.

Did I get this right?


Does the computer know when the car is in 1st or 2nd?
If so
How?

Almost:

1 correct
2 well yes, but there's a brake switch that that 12v goes through, so when you press the brake pedal that 12v is lost, thus temprarilly unlocking the TCC
3 correct
4 correct

[TURBOPOWERED68]

Originally Posted by TURBOPOWERED68

"ECM uses the park/neutral switch to know it's in gear"

i could wire in a switch but to which wires?

Originally Posted by TurboDave

Almost:

1 correct
2 well yes, but there's a brake switch that that 12v goes through, so when you press the brake pedal that 12v is lost, thus temprarilly unlocking the TCC
3 correct
4 correct

thanks i did wire in the brake pedal switch.

could i check the constant positive with just the key in the on position with out turning on the car.

also what about the above stuff?

[TurboDave]

Originally Posted by TURBOPOWERED68

thanks i did wire in the brake pedal switch.

could i check the constant positive with just the key in the on position with out turning on the car.

Yes.

also what about the above stuff?

Cant answer that, I'm at work now and haven't any reference material handy.

[SRGN]

The ecm gets a ground from the p/n switch when it's in gear. See the attached diagram.