200-4R electrical wiring and part identification

[Dad's El Camimo]

Hello, I am new to the list and I have a 1987 El Camino that I inherited from my father. I need to identify a wiring connection inside of the transmission case. It has two brown wire and two black wires. Would someone tell me what the part is and what its function is; which may be obvious by its name. The Torque Converter Overall.pdf has a wiring schematic with the part in question in the upper right hand corner circled in red with my questionable part.

I forgot to note the transmission is a 200-4R.

Thanks in advance.
John

 

[ELCAM]

Sorry I do not understand the drawing, can't help on that.

The picture is of the temperature switch.

 

[Dad's El Camimo]

Sorry I do not understand the drawing, can't help on that.

The picture is of the temperature switch.
View attachment 254100

The drawing shows the wiring from the case connector to the temperature switch you identified for me.
Thank you!

 

[307cutlass]

Uhmmm... Yes I agree with the response, according to the illustration in the pdf, it is the temperature switch. I think it's also called a temperature limit switch. But Iw anted to ask you Dad's El Camino, for what reason are you asking? Are you wanting to replace it, and if so, what is the symptom? Just curious as I had the TCC problem in my cutlass.

 

[69hurstolds]

Sometimes called an overheat switch. Not used in all models. In fact, I think it was later models and mainly Chevy. The idea was that if the transmission oil temp was above the setpoint (to which I have no idea what that is), the switch would close automatically locking up the torque converter to reduce slippage to help cool the fluid. Then below setpoint reset, again, whatever temp that was, the switch would open and resume normal operation. I think 700-R4s had them as well. Maybe not all of them, though.

AFAIK, Olds never used it. Could be wrong, but I don't ever recall it being used on Olds but I could be wrong.

 

[Dad's El Camimo]

Uhmmm... Yes I agree with the response, according to the illustration in the pdf, it is the temperature switch. I think it's also called a temperature limit switch. But Iw anted to ask you Dad's El Camino, for what reason are you asking? Are you wanting to replace it, and if so, what is the symptom? Just curious as I had the TCC problem in my cutlass.

I am glad you asked. No, I am not planning on replacing it. In 2011 a rebuilt transmission was installed by a local shop. It recently started leaking fluid at the case electrical connector. When I pulled out the old connector I noticed there were three wires on the outside plug and three wires on the inside plug. However, there are only two pins on the back of the case connector. Pins A and D, which power the converter clutch solenoid.

The B connection is a green with white stripe wire, on the wiring harness from the ECM. However, the connection terminates at the case connector because there is not a pin on the connector inside of the case for the brown wire that connects to the temperature control limit switch. From that switch, a brown wire goes to the internal pressure switch.

So I am wondering if the internal pressure switch and temperature limit switch are functioning. What also confuses me, is that I have read the green with white stipe wire could be for the 3rd or 4th gear switch which is labeld as the "internal pressure switch" in the attached wiring schematics.

Because there has not been a connection to the ECM since the transmission was replaced, I am wondering if I should connect the ECM wire to complete the circuit or leave things as they have been. I drive the El Camino less than 1000 miles a year and usually in city or freeway traffic. I don't know if something will be damaged by connecting the ECM wire.

The transmisson number is 006-871CCF0336 and there is a large F on the identiy plate if that provides any helpful information.

Puzzelled,
John