Relay is switching, but not running pump

Hi all, I’m pretty new to Arduino and electronics and am having trouble with an automatic watering system I’m trying to make.
The pump should run after meeting the conditions that 1) there is sufficient water level in the tank, and 2) that the delay has exceeded the input value determined by a pot. The pump will then run for a time based on an input from a second pot. The water level is checked by a float hanging off a lever action micro switch.

I’m supplying the circuit from a 12 V 7.0 Ah battery. This feeds a DC-DC step down regulator to supply the Arduino, and also directly supplies a SRD-05VDC-SL-C relay. The relay then powers a pump requiring 12V and 350 mA. The relay is connected to C (from battery) and NO (to pump). Circuit layout attached, which isn’t perfect…

I am able to get the relay LED to turn on and can hear the relay switching, however the pump doesn’t run. I have tested the pump separately and it is working. I have tried re-routing the low voltage +/- from the Arduino to the relay to come directly from the DC-DC regulator, however the regulator then emitted a high pitch sound, and it still did not work…

Am I using the correct relay? Can the relay low voltage +/- come from the Arduino?

Any help is appreciated…

Dont use I/O-pin to engage the relay… (The coil want 70mA@5V)
Add a transitor (and a base resistor) to keep current from I/O-pin < 20mA
A logic level N-MOSFET will also work