When I switch off my car, the pump goes on even the switch is off ion the gauge.
 

... Switch is off on my gauge !

Very annoying as it will drain my battery.
Please help
Thx

Re: When I switch off my car, the pump goes on even the switch is off ion the gauge.
 

You must only connect the red wire of the grey harness to a switched +12V source: only active at the "pre-crank" key position. Read page 11 of the user manual again.

Re: When I switch off my car, the pump goes on even the switch is off ion the gauge.
 

I have connected the wire to the Injector + as per the installation picture.
shall I change it a switched +12V source?

Re: When I switch off my car, the pump goes on even the switch is off ion the gauge.
 

This weird...

The entire HFS-3's power in control is activated by the red wire of the grey connector. As far as I know, the fuel injector (+) should not be "live" when you switch off the car.

Is your car a factory standard.

Just to certain, can you check the injector(+) for me to ensure there is no 12V present there when you switch the engine off.

Re: When I switch off my car, the pump goes on even the switch is off ion the gauge.
 

I put it as you said on the 12 V source and it works fine.
Thx

Re: When I switch off my car, the pump goes on even the switch is off ion the gauge.
 

Has it solved the "car switch off" problem?

Re: When I switch off my car, the pump goes on even the switch is off ion the gauge.
 

Yes it solve the problem. Thanks