I have no temp indication on the dash guage.

There's two coolant temperature sensors, one for the gauge and one for the Engine Computer. Did you replace the sensor with one or two wires?

The gauge uses the single-wire sensor. There must not be any teflon tape on the threads to seal it against leaks because that will insulate the ground circuit. To bypass the sensor, unplug the wire and ground it to the engine. With the ignition switch turned on, the gauge should read full hot. If it doesn't, there's a break in the wire or a problem on the instrument cluster.

Different places on different size engines, but it's usually near the thermostat housing too. Here's a photo of it from rockauto. Com.

Trust me when I tell you that it is the guage itself. You can either replace the guage or the instrument cluster? I had the same problem with my 95 F-150 so I replaced the sender thinking that would fix it nope so I did some testing and the guage itself was bad.