The bottom hose should heat up too indicating coolant flow. While the fan runs, the lower hose is cooler than the top hose.
The coolant sensor mounted on the radiator signals the fan to start/stop. When no coolant or heat is sensed by the sensor, the fan may not run at all, a known good sensor that is.
With the bottom hose remaining cold or cool, same as no flow thru the radiator. Either the radiator is clogged, coolant pump not pumping, a restriction on bottom hose such as colapsing hose and chocking or something along the line.
You may want to disconnect both top and bottom radiator hoses and run a garden hose water flow thru it (radiator) and watch the flow. Or disconnect te top hose, run a garden hose instead in the radiator side, and watch the coolant drain out the top hose, would drain in surges as thermostat opens and closes with temperature change. verify coolant flow anyhow possible.
Save good/used coolant/antifreeze, do not contaminate the environment. Final coolant fill, distilled water is prefered as to avoid minerals in the coolant system, minerals found in tap water.
When it is timing belt time, get the water pump replaced too since there are current cooling problems. The bottom hose should heat up too indicating coolant flow. While the fan runs, the lower hose is cooler than the top hose. The coolant sensor mounted on the radiator signals the fan to start/stop. When no coolant or heat is sensed by the sensor, the fan may not run at all, a known good sensor that is. With the bottom hose remaining cold or cool, same as no flow thru the radiator. Either the radiator is clogged, coolant pump not pumping, a restriction on bottom hose such as colapsing hose and chocking or something along the line. You may want to disconnect both top and bottom radiator hoses and run a garden hose water flow thru it (radiator) and watch the flow. Or disconnect te top hose, run a garden hose instead in the radiator side, and watch the coolant drain out the top hose, would drain in surges as thermostat opens and closes with temperature change. verify coolant flow anyhow possible. Save good/used coolant/antifreeze, do not contaminate the environment. Final coolant fill, distilled water is prefered as to avoid minerals in the coolant system, minerals found in tap water. When it is timing belt time, get the water pump replaced too since there are current cooling problems.

**"thru it" - radiator **"thru it" - radiator