I'm not sure where to start because I'm running out if time where I'm using their wireless internet. There's too much I want to cover, and it takes a while to look up the information you need. I'll get as far as I can to get you started.
You're right to find two terminals for the pump relay to have 12 volts all the time. They're tied together. One is the high-current supply that gets switched onto the pump's feed wire, and the other one feeds the relay's low-current coil. Of the other two, the small black wire gets grounded by the Engine Computer when it wants to turn the pump on. 12 volts gets switched onto the green wire that runs to the pump.
The easiest, since you're already down by the pump, is to look for that green wire. A test light is much better for this than a digital voltmeter because you can see the light easily and it puts a load on the circuit. A break in the wire that is bridged by a little carbon track will be picked up by a voltmeter and falsely say the circuit is okay. No current will get through that break to run the pump OR the test light, therefore, the test light is more accurate. You can unplug the connector and stick the probe of the test light in there. Watch if the light turns on for one second, then again when you crank the engine. If it does turn on during cranking, you've eliminated everything but the pump and its ground wire. 99 percent of dead fuel pumps are caused by those two sensors which also cause no spark. Since you have spark, all that stuff is known to be okay too.
There is no common problem on Chrysler products with the fuel pump's ground circuit, so while we should check it, the pump is the likely suspect, especially at the mileage you listed.
As for bypassing the relay so you can work on the circuit, you can use either terminal with 12 volts all the time for the supply, then just touch the jumper wire from there to each of the other two terminals. At some point those other two terminals are going to have 12 volts on them so jumping it there won't hurt anything. Do that though with the ignition switch off so the computer will never try to ground that jumper wire in an attempt to turn on the missing relay.
Friday, March 6th, 2015 AT 6:52 PM