I just have the new water temp sender to play with right now, trying to check the sender with an ohm-meter just shows an open circuit, both hot and cold, might be faulty then?
If it reads open from the terminal of the sender to the case of the sender it is bad. It should read about 70-80 ohms room temp, about 10-20 hot (engine warmed up).
So yours may be bad out of the box. Same thing happened to me.
