Wondering if anyone can help me on this please.
I have a 320lph in tank pump running to a bosch 044. When the heater blowers are turned on the note of the pump changes and when the indicators or rad fan turns on. Only thing is the pump doesn't make this noise if the fuel tank is full. It only really starts just above half a tank. I'm using 10g cable for the 044 but standard wiring for the 320. Does the standard cable need to be upgraded or am I barking up the wrong tree? Hope you people can shed some light on this. Thanks

 

the stock wiring is often barely capable of powering a 255lph pump and the 320 I would think draws even more current. When I ran larger than stock pumps I setup a relay and powered the pump on its own larger gauge wire, using the original power wire as the input signal to the relay.