No power going to fuel pump

[sirsmokeallot]

A couple of weeks ago i was driving home and the car stalled and would turn over but not start, got the RAA down to diagnose, and he said that the fuel pump nees to be replaced. when u turn the ignition on, u could not here the fuel pump engage.
So i replaced the fuel pump, and tested out the old one that i pulled out and it still works! wtf

What ive tested so far....
#Ran i self diagnosis and got 12 Satisfactory operation (alltho i did this after having replaced the old fuel pump and the battery negitive was disconnected during, so probably lost all previous codes)
#checked fuses, all good
#Bridge terminals D and B to a test light. it illuminated for 2 seconds so fuel pump relay and fuel pump circit are working. (i think)
#Bridge terminals C and D and turned ignition on-fuel pump still didnt work
#disconnected wiring connector near the Fuel gauge sender unit and tested that with a lamp, and C and D bridged and test lamp worked, was getting power.


Furthermore, I have also tried to bypass computer and give power straight to the pump (the purple wire) and no power to the fuel pump at all

Any ideas on what to do next, please help me out! no power to the pump, but power down there (connector at sender unit) when i bridge D and B on Diagnose connector, i dont get it!
what could cause a fuel pump that works, not work?

Thankyou for your time.

[wortus]

Fuel pumps that are no good can still run out of the car, this hapened to mine when it broke down and could not be coaxed back into life. I took it out, put power onto it and it ran.
To bypass the wiring and apply voltage to the pump all the time you just pullout the fuel pump relay and put a jumper wire into the 2 pins on the socket base that correspond to the normally open contacts of the relay itself. One of these pins will have +12V on it all the time or at least with the ignition turned on, can't remember which it is.
If there's +12V in the socket and you jumper the pins and the pump doesn't run and assuming the pump is OK then you will need to get under the car and look at the wire for any damage and test it at any plugs and sockets for voltage and earth continuity.

[sirsmokeallot]

Thanks for the reply Wortus.
I fixed it, turns out for some reason the custom alarm was blocking it, i was only getting 1.45Vat the pump and 13V at the relay.
So i cut the alarm out the picture by connecting the violet wire back to its original form, therefor bypassing fuel pump passed alarm.