No sound from the fuel pump. Checked all fuses, voltage at fuse box ok, changed the fuel pump assembly and still no action from the fuel pump.

Have you checked for spark? What led up to this? Which color wire are you finding 12 volts on, and what do you have to do to find it there?

Are you sure this is a 2.7L? Is this an LX model or LXi?

The fuel pump wire is green / white. There's a separate relay too. Start by bypassing that relay to see if the pump runs. You can also test for voltage that way without having to crank the engine. You can install the relay with the cover removed, then squeeze the contact, or you can remove it and use a stretched-out paper clip to jump terminals 30 and 87 together.

The relay isn't the issue. You have to BYPASS it to allow you to troubleshoot the circuit.

All cars have a means of turning the fuel pump off when the engine stops rotating. Chrysler calls theirs the automatic shutdown, (ASD) relay. The Engine Computer turns that relay on for one second when you turn on the ignition switch, then again during engine rotation, (cranking or running). The computer knows to do that by the signals it receives from the crankshaft position sensor and the camshaft position sensor. Those signals also synchronize the firing of the injectors and ignition coil(s).

The ASD relay sends current to the ignition coils, injectors, oxygen sensor heaters, alternator field, and the fuel pump or pump relay. This is where way too many people get hung up on the first thing they find missing. For some reason that is usually the fuel pump, possibly because more observant owners know they should hear the hum of the pump for that first one second, and they notice they aren't hearing it now. Actually, a loss of spark is responsible for about one percent of cranks / no-starts, and a dead fuel pump is responsible for perhaps another four percent. That leaves 95 percent of no-starts caused by a loss of both fuel and spark. That's why when you find one of them missing, it's important to check for the other one.

If you bypass the fuel pump relay with a piece of wire, or pop the cover off and hold it turned on with a rubber band, you should hear the fuel pump running. The ignition switch doesn't have to be on for that. This is a quick test to tell if that circuit is okay. If the pump runs, there's no need to troubleshoot that circuit.

If "it" is the fuel pump relay, and the pump still didn't run, then we do indeed have a problem in that circuit. Keep that relay bypassed, then go in back and check for 12 volts on the green / white wire at the pump's connector. That is done most accurately with the plug still connected, but I realize that's hard to do. I prefer to back-probe through the rubber weather seal. I never approve of cutting a wire's insulation or poking through it to take a reading. If you have to unplug the connector, a test light will be more accurate than a digital voltmeter. You can have a wire almost completely broken except for one remaining strand, and the voltmeter will gladly detect 12 volts, but you can't get enough current through that one strand to run the pump. The test light won't be happy with that one strand either.

If you do find 12 volts there, we'll have to test the ground circuit. That's normally a black wire, but I'll have to go back to the wiring diagram to check for sure.

Be careful if you test with the connector unplugged if you go into the terminal that you don't poke so hard that you spread that terminal open. That's a common cause for a bad connection to the mating terminal on the other half of the plug.