VDO electric fuel pump wiring

[chipis]

Hello,
now im converting back to carb system while the EFI system was removed. But at the moment i cannot remember how this electric VDO pump was connected, there are no spare plugs left for it, it has three wires i dont know what the third wire could be for? As i understand one should be for a ground, secong for a 12V and third for what? Where should this unit be connected?
Also on the left there is ruber hose going down, so it should be for a boost pressure?
attaching the photo of the unit:

Would appreciate any help!

[TopCat]

Just a guess (from experience with fuel systems)

It's probably an 12v ignition feed, most fuel systems will have a solenoid which require a 12v pull in & a 12v hold in.

Tough to say with out seeing it.

[chipis]

I do also think that here should be 12V constant powes, ignition and ground, just want to confirm. also regarding ruber hose on the left which goes from the unit, there should be connected boost line or some kind of fuel return hose?

[chipis]

Maybe for anyone in the future it will be useful:
as i found out this is not a pump, this is fuel flow sensor sending info about fuel consumption to the incar display