Originally Posted by R5FORD
so basically run a 12v wire from the battrey? or the existing relay to the rear and just conect it into the original wiring at the fuel pump?
Easiest place to put the relay is at the rear of the car.
Wire from Battery to new Relay to supply IN of Relay. Put in-line fuse in right by Battery so if the wire chafes, it doesnt cause a fire. Will need to be sensibly sized fuse (to match original requirements of the pump - I think 30Amps will Do it).
There are two wires that connect to the fuel pump - plus and minus. Minus is earth (IIRC). Check that you have good continuity to earth. If not - replace this wire with new strap to good metalwork. Also earthy Relay.
Cut off wire from + terminal. This is now your signal wire. Put this onto the Signal terminal of the relay.
Finally put a good quality cable from the Output of the Relay to the pump + position.
This way, whilst the signal of the original plus cable is not necessarily good enough to power the pump properly, it will be good enough to tell the relay to do so.
Job done!
Then switch car on, and test voltage across the fuel pump with a Volt meter.
JJ
Buy New relay. Put relay in boot area somewhere safe. Many attach to the