What should the voltage at the fuel pump be at idle and through the rev range, thinking of getting a new loom. Wanted to check it first to see what it's at now.

 

I think it should read the same as the battery - alternator. It should be something between 12 and 13.8 volts. It will likely drop as the load rises, but in my opinion anything under 11 - 11.5 requires a rewiring

 

Ok cheers for that fela, it's doing about 12-12.5
Might make a new loom anyway just for piece of mind

 

If you make your own loom, don't forget to get nice and thick wires. The fuel pump draws a fair amount of power, and is a long way from the source.

 

The power at idle is not the issue.

You need to test it under load (When the pump draws more current) you should not see much of a drop...

Martin

 

I made my own loom with 6mm wire from battery and 70amp reley and i have 13.1V at idle!

 

Cheers for the advice felas

 

Its a 12v unit so as long as you have at least 12v under full load you should not have a Problem.