First picture shows the Tim capillary temp gauge that I bought off Ebay for £20 it does not rely on electricity to show the temp and even with the engine off shows how hot it is. It fits in place of original.

Second pic shows the Gauge does plug in where original sensor was and also shows the Fiesta thermo cap which bolts straight on, the plugs have to be bent down due to bonnet line.

The overflow is plugged into a VW expansion bottle that has a drain plug that goes down to a tee piece let in to the lower rad hose which is the return to engine (like all modern cars).

The electric fan was new off Ebay for £25 and is well able to cool the rad it has a manual overide in the car and is also operated via a relay by the Fiesta thermo cap sensor.

Shown also is the top small rad pipe that I have blanked off.
Do I get any overheating? no.
Does the fan come on in traffic jams? yes. After about ten minutes! the car runs at about 82 degrees most of the time and the gauge can show early if something is going wrong, which on track work can happen

Strangely my Ford Pinto engined Robin Hood runs hotter than the Sprint.