... if I drive my 82 T/A (THM 200C) with the electrical connection to transmission disconnected? I decided to do this last week because the torque converter was remaining locked (and would only unlock just before the car came to a stop). Disconnecting has solved the problem.

I've received two very different opinions on whether the car should be driven in this condition, both from knowledgable mechanics. The first explained that the lock-up feature was only for fuel economy and there is no harm in driving the car without the connection to lock-up solenoid. On the other hand, I was told today by a different mechanic that the converter will run too hot in third gear without the lock-up feature engaged and that I will burn up the transmission fairly quickly driving it in this condition.

I am not that knowledable about transmissions and will likely have the solenoid replaced in the near future to address the problem. Just wanted to know whether I am doing immediate harm to the transmission if I continue to drive around without the lock-up feature. Thanks in advance,

 

Depends.
The early T700 trans (<'86 ? ) only had full fluid flow to the cooler when the convertor was locked ,which is where all the horror stories about burning up your T700 with no lock up started from
The whole trans got hot , not just the convertor ;
The later versions had full fluid flow anytime so it didn't matter if lockup was engaged or not.
Given the 200 was built in similar period (even earlier ) than the early T700 I would go with the 2nd opinion
FWIW
The GM 3 spd autos had no lockup at all and they never burnt up under normal driving.


That only hid the problem.
Have you done anything to determine why the TCC is engaged, checked the wiring / switches that operate the lockup ?

 

The 700-R4 can; the 200-4R does not burn up without lockup. A TH200-C has similarities to the 200-4R but a different pump and valvebody so the 200-4R is not a valid indicator either way.

The 700-R4 and 200-4R are a relatively easy solenoid swap after dropping the pan. The 200-C requires trans. out / pump removal.

 

The 700-R4 and 200-4R are a relatively easy solenoid swap after dropping the pan. The 200-C requires trans. out / pump removal.

Thanks - wish that weren't the case, but when I found out that to replace the solenoid on the 200C requires removing the trans, I decided to temporarily disconnect the solenoid.

Have you done anything to determine why the TCC is engaged, checked the wiring / switches that operate the lockup ?

Not yet, but would like to. Trying to figure out where to begin to troubleshoot. From a visual inspection of the wiring, it looks fine. How should I go about troubleshooting the switches that operate the lockup? Thanks again,

 

put a 12v test light on the wire going to the trans. The ECM should command lockup under steady TPS signal, warmed up temperature value, and above a certain speed. If it's doing that, and unlocking under hard throttle / low speed, then the circuit isn't the problem.

A bad solenoid isn't uncommon. Also, there is a 3rd gear pressure switch listed for the TH200-C which may or may not have been used in 82. This is an item that lives longer than the solenoid most times, but depending on how your trans. is wired, it's not a bad idea to replace it when the 'noid is done.

 

will post a new issue

 

put a 12v test light on the wire going to the trans. The ECM should command lockup under steady TPS signal, warmed up temperature value, and above a certain speed. If it's doing that, and unlocking under hard throttle / low speed, then the circuit isn't the problem.

A bad solenoid isn't uncommon. Also, there is a 3rd gear pressure switch listed for the TH200-C which may or may not have been used in 82. This is an item that lives longer than the solenoid most times, but depending on how your trans. is wired, it's not a bad idea to replace it when the 'noid is done.

Thanks again! Will try this over the weekend and post what happens.