- Jun 6, 2020
- 91
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Lockup torque converter kit
- Thread starter Rocket350olds
- Start date
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The wiring at the connector is likely different and you might not need the pressure switch if it already has one in the pan. You might not need any pressure switch if it has the governor switch installed.
You need to know is it early 2 pin connector or later 4 pin?
Does it have the pressure switch on the valve body?
Was it computer controlled or not?
You need to know is it early 2 pin connector or later 4 pin?
Does it have the pressure switch on the valve body?
Was it computer controlled or not?
- Jun 6, 2020
- 91
- 18
It has 4 pin connector and no governer switch and it was computer controlled recently until I removed ecu and harness
From a Mitchell transmission rebuild manual the 200-4R and 700R4 is pins A (+) and D (-) to the TCC solenoid so it should do the job as is.
Problem I see is there is no 3rd gear pressure test port on the case. Hydraulic diagram in manual only show line pressure test port.
If it proves not to have the external 3rd gear test port I see two options:
Did your computer set up have a wire on terminal B? If so use the internal 3rd gear pressure switch. Usually these are one terminal grounding switches ( might want to verify this by putting an ohm meter on the B pin and ground and see if the switch closes when in third gear.) so you would connect pin D to pin B so the TCC grounded through the 3rd gear pressure switch.
Or install a governor pressure switch, a one terminal would hook to the TCC solenoid ground, a two terminal would have one terminal to the TCC ground with the other terminal runout to the 4 pin connector pin D.
Problem I see is there is no 3rd gear pressure test port on the case. Hydraulic diagram in manual only show line pressure test port.
If it proves not to have the external 3rd gear test port I see two options:
Did your computer set up have a wire on terminal B? If so use the internal 3rd gear pressure switch. Usually these are one terminal grounding switches ( might want to verify this by putting an ohm meter on the B pin and ground and see if the switch closes when in third gear.) so you would connect pin D to pin B so the TCC grounded through the 3rd gear pressure switch.
Or install a governor pressure switch, a one terminal would hook to the TCC solenoid ground, a two terminal would have one terminal to the TCC ground with the other terminal runout to the 4 pin connector pin D.
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- Jun 6, 2020
- 91
- 18
What year, make and model car is it? Perhaps a wiring diagram will help here.
Looks like it is A B and C being used so if nothing else you would need to change one of the wires on the kit to make it work since it is A and D.
This is why these kits are never advertised for the C version of the three speed transmissions, they are all wired in some weird PITA way.
Just a guess:
Orange is usually +12 volts not switched in GM land, but can be other things.
Purple is the 3rd gear pressure sensor and should go to the computer. It will close the switch grounding the circuit telling the computer it is in 3rd gear.
Green w/white stripe is probably ground, the computer grounds this wire to enable the TCC solenoid.
Need to verify this to be 100% before i would wire anything.
Looks like it is A B and C being used so if nothing else you would need to change one of the wires on the kit to make it work since it is A and D.
This is why these kits are never advertised for the C version of the three speed transmissions, they are all wired in some weird PITA way.
Just a guess:
Orange is usually +12 volts not switched in GM land, but can be other things.
Purple is the 3rd gear pressure sensor and should go to the computer. It will close the switch grounding the circuit telling the computer it is in 3rd gear.
Green w/white stripe is probably ground, the computer grounds this wire to enable the TCC solenoid.
Need to verify this to be 100% before i would wire anything.
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- Jun 6, 2020
- 91
- 18
It appears the trans go picture above is incorrect for the pin assignments, that sure was confusing. This is from a GM manual page for 200c, 250c and 350c
Is the wire I am calling orange actually tan with a black stripe? Must be half color blind here. If it is I think it goes like this:
A - Purple is +12 volts and went to a switch on the brake light switch (when brakes are applied the power would be switched off.) then to a +12V source.
B - Green with white stripe is the 3rd gear switch to the computer.
D - Tan with black stripe is the TCC solenoid ground controlled by the computer,
It looks like the kit you want to use would go to A and D and would be correct but you would have no 3rd gear switch so it would want to lock up all the time.
Pretty sure you could hook D to B and ground through the 3rd gear switch and that would solve that. Would also keep the brake switch on the +12V if I was doing it, and perhaps use a vacuum switch like the trucks and pre computer cars used so it would not lock up if the engine is under load, or when the transmission is not in 3rd gear or the brakes are applied..
Non CCC TCC setup. (Thanks to ribbedroof who originally posted this diagram here.)
Confused yet?
Is the wire I am calling orange actually tan with a black stripe? Must be half color blind here. If it is I think it goes like this:
A - Purple is +12 volts and went to a switch on the brake light switch (when brakes are applied the power would be switched off.) then to a +12V source.
B - Green with white stripe is the 3rd gear switch to the computer.
D - Tan with black stripe is the TCC solenoid ground controlled by the computer,
It looks like the kit you want to use would go to A and D and would be correct but you would have no 3rd gear switch so it would want to lock up all the time.
Pretty sure you could hook D to B and ground through the 3rd gear switch and that would solve that. Would also keep the brake switch on the +12V if I was doing it, and perhaps use a vacuum switch like the trucks and pre computer cars used so it would not lock up if the engine is under load, or when the transmission is not in 3rd gear or the brakes are applied..
Non CCC TCC setup. (Thanks to ribbedroof who originally posted this diagram here.)
Confused yet?
Last edited:
- Jun 6, 2020
- 91
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