How to tell if fuel pumps are running by current draw?

If they are having that many issues with vapor locking they are attempting to rig up a gauge just to determine if the fuel pump is operational, I would just tackle the symptom of heat in the engine bay. That is assuming they already troubleshot the issue and determined it is a vapor lock and not a fuel delivery problem. Just because the pump is running does not mean it is delivering adequate fuel pressure under load.