How di i rewire a fuel pump - 1986 Subaru XT

All modern pumps run neg to earth, some pumps have two connections Neg -, and Pos +. Others have one terminal and are earthed through the metal body of the pump. so the live cable goes to the + terminal of the pump.

Are you sure the inertia switch has not cut off the power to the fuel pump?

Take it to a ASE certified repair shop . No one on here is going to know with out looking at it , How do we know what was rewired an how they did it, who rewired it ? You don't mess with things if your not sure what an how they work ! . It blows fuse # 1 in the power distribution box ? This is the fuel pump fuse ! What solenoid ? or do you mean a relay ? fuel pump relay ?

Make sure it has not been rewired

Go to the LINK for a full discription with pictures of the removal of the fuel pump and sender.

First things first...Rewiring the fuel pump will only put a "Bandaid" on whatever the problem really is and will most likely create a situation where wires are draped across places where they shouldn't be, causing all kinds of future electrical problems. I have had to clean up that type of mess too many times.That type of "shade-tree" repair makes proper diagnosis and repair of a vehicle nearly impossible, even by a trained technician. My recommendation: DON'T EVEN THINK ABOUT IT!

OK, Now that I have my preaching out of the way...
The check engine light is supposed to come on every time you turn the key to the "On" or "Run" position before starting the engine. This is for a "bulb-check" just to let you know that it is not burned out. It should go out immediately after the engine starts and should stay off the entire time you are driving the car. It is not any type of indicator to let you know that the fuel pump has run. If your check engine light is not coming on every time you turn the key to "On", then there is probably a problem with your ignition switch or your ECM Main Relay. Either of these can cause an intermittent failure of the ECM to power up, a)d thus, not turn the check engine light on. Failure of the ECM to power up will also cause the fuel pump to not run because like the check engine light, the fuel pump is controlled by the ECM. (Rewiring the fuel pump will not make the engine start if this is in fact what the problem is.)

I have also seen many fuel pumps that run when they want to. You could have a bad fuel pump, but refering to your statement about the check engine light, I would guess that the fuel pump is not the main problem or even if it is a problem at all.

well...assuming you are talking about the fuel pump being rewired then you possible suspects are...
1.) fuel pump relay
2.) computer
3.) any all wires from computer to relay and/or fuel pump

rewire it to teh ignition switch

Did you put in a complete fuel pump assembly which included a new fuel level sender?
May be a defective fuel sender on the new pump assembly.
Did you have to rewire anything/change plug at fuel assembly?
May be bad connection or wrong connections.

Ignition switch.