The stock trans temp sensor is basically useless. If the trans gets hot enough to cause the warning light to come on it is damaged. If the trans is too cool the PCM won't let it shift into OD which is a PITA.
Pull the connector off the stock temp sensor and put a 1K resistor in it. That will satisfy the PCM that the transmission is warm enough to allow OD. Then put your aftermarket temp sensor where the stock one was. That puts the sensor in the hot cooler line which is where you want it. This won't work for '96 or later trucks (47RE transmission) because the cooler line is not the same as for your '94 with a 47RH transmission.
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