Sorry, I missed seeing this thread. The thermocouple generates a very small voltage in proportion to the difference in temperature from its tip to the end of the leadwire. You need a digital voltmeter with a millivolt range on it to read the value. With the engine idling (exhaust gas temperature approximately 300°F) and the end of the leadwire in the vehicle interior at approximately 70°F, you should measure approximately 5.28 millivolts.
Regards,
Michael Pliska