Engine not running

You replaced the Engine Computer. That means the 12 volt memory circuit was bad. That is why there are no fault codes. Removing the computer or disconnecting the battery erases the codes, then that valuable information is lost. Resetting fault codes has nothing to do with a drive cycle, although some defects are only detected under certain driving conditions. That can include codes related to the crankshaft position sensor and camshaft position sensor. Often the missing signal from one of those is only detected while the stalling engine is coasting to a stop. Those codes may not set by simply cranking the engine. You need a scanner to view live data to see if those signals are arriving at the Engine Computer. I have a Chrysler DRB3 scanner for all of my vehicles. That lists each sensor with a "No" or "Present" during cranking. Codes for electrical problems, like cut or grounded wires, and some sensor failures, will be detected the instant you turn on the ignition switch, and the fault codes will set at that time. Do you know how to read the codes yourself without a scanner?

You can verify if one of those sensor signals is missing without a scanner. Use a test light to check for the 12 volts. Most digital voltmeters do not respond fast enough for this test. Back-probe through the electrical connector for either coil pack, any injector, or either of the two smaller terminals on the back of the alternator. The correct wire is the one that is the same color at the coils and every injector. Typically that is the dark green/orange wire. You will see the test light turn on for one second when you turn on the ignition switch. What is important is if it turns on again during cranking.

If you do not get 12 volts during cranking, you will not have spark, injector pulses, or fuel pump.

Did you do the voltage check I described? We need to know if the ASD relay is turning on during cranking.

Did you read the fault codes?

Fuel pressure is not a valid clue because it will be normal due to the fuel pump running for that one second when you turn on the ignition switch.

If I may jump in here, I would check for system reference voltage to see if the computer system is powering up on the sensor side, next disconnect all monitoring sensors such as coolant temperature and O2 sensors just leave the basic sensors such as crank angle, ignition and injectors. We are trying to see if the computer has any life in it without the disruption of outside sensors, one might be shorted causing the system to shut down. Here is a wiring diagram to check the system out. Turn the key on and test the dark green and red wire at the coil and injectors for 12 volts.

Please let us know what you find so it will help others.

Best, Ken

The only way the oxygen sensors are tied to the ASD relay is that relay sends current to their internal heaters. If the heater wire is shorted to the ground wire at one of those sensors, it will cause a fuse to blow or a fuse link wire to burn open. Neither of those will be intermittent.

As a comment of value, multiple clicking relays is a common symptom of a run down battery, or a battery with a shorted cell. Check the battery voltage with a digital voltmeter. If it's good and fully-charged, it will be 12.6 volts.

You really need a scanner to see what is taking place with the ASD relay. You can check the coil terminals too with a voltmeter. First verify there is 12 volts on terminal 86 when the ignition switch is on. You can do that with the relay removed from the socket. The next step is to see if the computer is grounding terminal 85. Normally I'd use a test light, but most of them draw a lot more current than the coil in a relay. I don't know if the circuit in the computer will be damaged by a test light. Also, to be accurate, the relay needs to be in the circuit. That means you need to lift it out of the socket just enough that it's still plugged in, but you can reach terminal 85 with the probe. With the ignition switch on, you should see 12 volts there, (coming through the relay's coil). That should drop to near 0 volts during cranking. If it does, the computer is turning on the relay. If that voltage is pulsing, there's a problem with the signal from the cam or crank sensor.

If the relay is buried or surrounded where you can't reach a probe to the terminal, insert a wire in the socket's terminal, then plug the relay in. You can use the wire for the test point, but you have to be very careful. A fat wire, plus the relay's terminal, can stretch the socket's terminal to the point it makes intermittent contact and you have another intermittent problem in the future. Stretched-out paper clips work well if there's room, otherwise use one or two strands of wire from an old power cord. Those are much too thin to cause a stretched terminal.

The EGR is not related to this problem. It is monitored and problems are detected while the engine is running. None of the failures will cause the engine to stall.

I'm not an expert on any scanner other than the Chrysler DRB3 that I use for my vehicles. That one lists the optional circuits in use on the vehicle it's currently connected to, and if one is missing, it won't display any codes that might be set related to it. The older DRB2 would ask you, for example, if the car has air conditioning. If you answer "No", it will not display the code for open compressor clutch relay circuit. If you answer, "Yes", it will display that code on cars that don't have AC.

The engine numbers don't mean anything to me, but they might to the people in the dealer's parts department. One thing I CAN offer is if someone did replace the engine, AND the flex plate, and the engine never ran after that, you likely have the wrong flex plate. I don't know if this applies to the V-10 engines, but it is a common sore point with the V-8s. Some of them have four groups of four square notches in the ring welded to the flex plate. The crankshaft position sensor sees those notches by generating a voltage each time a notch passes by it and disturbs its magnetic field. The Engine Computer needs to see four pulses, a gap, four pulses, a gap, ... To know when to fire an injector and a pair of spark plugs, (one ignition coil), and it needs a different signal to know WHEN to fire which coil and injector. That is normally known by the signal from the camshaft position sensor. The first spark plug will fire once a signal is received from both sensors.

A different variation, (this is from memory and will likely be wrong, but you'll get the idea), has four notches in the ring on the flex plate, a gap, four notches, a gap, four notches, a gap, then five notches. When the computer sees five pulses in a row, it knows when a specific piston is coming to top dead center, and it knows which ignition coil to fire. From then on, it calculates which ones come next and just fires them in order each time it sees four pulses. The clue here is the engine will crank but will not start until that series of five pulses arrives. That can make it appear the engine has a long crank time before starting compared to what some people are used to.

The clinker is those flex plates can be interchanged. That often happens when an engine from a different year is transplanted and the flex plate stays with it. You need to reuse the flex plate that came with the truck. I don't know how many variations there are for these flex plates. But you can be sure you have the right one if the engine ever ran. Using the wrong flex plate always results in a crank / no-start condition. That would be frustrating to have to repeat the repair procedure to replace it, but it would be interesting first to watch the voltage on the dark green / orange wire to see if the ASD relay is being turned on sporadically by the Engine Computer. I don't plan on testing that idea any time soon!

There's four ground wires. Two are for high-current items lie injectors and ignition coils. Two are signal grounds for sensor circuits. They will be bolted to the body someplace near the computer. I don't know exactly because I've never needed to find them. It isn't likely all four are bad.

Signal ground wire is A4. That is the wire all the sensors connect to. That wire is not actually grounded. It is the common ground circuit that goes TO ground after it goes through the Engine Computer. That is done so the computer can monitor it for proper operation. My diagram doesn't show the actual signal ground wires. To find that you'd have to find a paper copy of the manufacturer's service manual. That will have an entire section that shows every connector, every wire in that connector, its color and its function.

Two power ground wires are A31 and A32. They are black / tan wires that are spliced together, then grounded "in front of the engine". I don't know if that means on the engine block or on the core support in front of the engine. I've specialized in electrical diagnosis for decades, and as I mentioned, I've never had to look for the ground wires on a Chrysler product.