what would cause my temperature guage to stay at cold?

a shop can do a sweep test with a scanner to test the gauge unit. there is a gauge sensor under the hood as well that may be at fault. Roy

Could possibly be the temp sending unit. The coolant sensor is only for the coolant level, not for the temp. Most likely not the gauge voltage regulator as that would affect more than just the temp gauge. Are any other gauges not working?