'91 Jetta 1.6 na coolant temp gauge not working

[mx597turbo]

I just bought the car. Everything else on the cluster works. But the coolant gauge didn't move at all, it stayed all the way on cold. Does this sound like a bad coolant sensor or problem with the gauge?

Can I use a multimeter to check if the sensor is working? If so, what should the reading be is the sensor is properly functioning?