Like LXman said above, make sure you check stuff like block to chasis graounds too, they do come loose or corrode and break, it would really suck to buy the new ecu only to find a broken ground wire caused the problem---plus you're out the cash

 

I agree it would really stink to buy a ecu and it not be it, I did what I would call a thorough check over everything. I cleaned the few ground connections I could see but Im not entirely sure I got all of them. How many ground points are there and what are their locations?

I noticed something weird and I dont know if its a problem or not which it could very well be. Oddly enough the two power wires comming into the back of relay center, which I thought were what powered it I can't find any volatage between them (positive and negitive). I am however getting power to a few relays if Im not mistaken (reading them wrong) which I dont know how that would be possible if that truely is the only power feed comming in.

 

Go to Weeds profile and click on "about me" and get the FSM for your truck, sounds like you may need it. I'm not totally convinced that your problem lies in the PCM, you may be having issues with the front control Module/Power Dist Center (fuse box).
A number of guys have had issues with these in your year of truck, you might want to get real personnal with that before you lay out your cash, I would think that at the very least, you should have a power "constant to the PCM, and a separate power line feed when the igniton is on.

I don't really have a good answer on the grounds, but the FSM will, It'll also give you what you need as far as wiring too----a map of sorts.

Good Luck!!!!!

Chasing wiring problems can be a real PIA

 

Make sure your "cigar" fuse is good or a scanner won't work.

Check your fuel pump by turning the key to run(not start) and listening for the whine. You might need a 2nd set of ears.
If it's whines it's working. Then I would say check to see if you have a pressure regulator up on the fuel rail. The check ball might be rusted shut.
Do 03's have coil packs? Have you looked into that?

 

I am almost convinced this might just be one of those little problem areas dodge has. I think I need to read up on the issues other people have had with their PDC power distribution center, because Im like you I doubt its in the computer...not saying it isnt but some what unlikely. I agree wiring issues are a PITA feels like your getting no where sometimes

 

The issue is further upstream Im afraid. No power comming to the coil pack, no fuel pressure...havent even check to see if power was going to it because I just do see the truck loosing spark and fuel pressure all at once...it would be one heck of a coincidence. I think its related to PDC...CPU...or I dont know if Dodges have an oil proving switch like Chevys but I have ran into that before shutting down power to the fuel pump as well. Also my scanner does come on it just wont link to the vehicle, indicating to me...and correct me if Im wrong the computer isnt sending a message to it.

 

If the PCM is dead, you won't get anything from it, no codes-----nothing. See if you can identify the wires that power up the PCM, if you have pwer going to the PCM, but nothing out, its the PCM, if no power to it, may be from PDC or ignition switch