I have a 89 Mustang 5.0 LX that I just bought yesterday. Stayed at a friends house and today when I went to leave the car wouldn't start. I could not hear the fuel pump prime. Went and got some start fluid and the car started right up. So I then replaced the Fuel pump rely under the seat and nothing happened. However when I turned the car on I hear two click's from the fuel pump relay. Now I was told that the car had a brand new fuel pump and fuel filter so I don't believe that is the problem.

I need to get the car back home.... So my plan is to run a 12V on a switch from the battery to the fuel pump directly. My question is.... I know that you have to run it from the battery to the inertia switch (Which I also tried) My question is.... were exactly on the inertia switch do I run it. As in wire and all that good stuff. Pictures would be best.... but I kind of need an answer quickly because I'm pressed on time.

Any and all help would be most appreciated.

 

The inertia switch doesn't actually run to the pump, it runs to the relay on the red/black wire. When pin 2 on the relay is energized, it should switch and connect pins 3 & 4.

 

So does that mean if I connected the Pink and Black wire that goes to the fuel pump relay to a direct 12V wire to the Battery and it didn't prime.... does that mean the fuel pump needs to be replaced? Even though supposedly its brand new.

 

It means the fuel pump isn't turning on. Whatever is wrong from there is a guess until you drop the tank. Maybe the plug came out of the pump, maybe the pump is bad, maybe the wiring inside the tank came loose.

Drop the tank, put your wiring back to normal and make sure you have 12v incoming at the tank wiring harness with the key on. Go from there.

 

I assume I need to drain the fuel from the tank before this is done?

 

Yeah as much as you can. A large capacity, low profile plastic container will work well, you can dump it right in as you lower the tank. The bulk of the gas will come out when you're sliding the tank sideways to get the filler neck out.