Leaderboard

Look at the picture of the temperature sender. The "top" has come off - I could tell that from the black goo oozing out in your pictures. That black "wire" you're pulling out is the internal wiring to the thermistor. It's broken so you don't need to be gentle with it anymore! Pull it out and disconnect the yellow wire from the top of the sender... Remove the nut and pull out the rest of the sender from the thermostat housing. Buy a new temperature sender online or at your local parts store and get it installed. (Save the "hold down" nut just in case the new sender doesn't come with one.) Nissan used the same resistance value for these senders for many years of Z's (and ZX's).