Hello all, I’m really hoping y’all can give me some kind of direction here. Sorry, in advance, for the long post. Let me start by telling you what I’ve got and what I know. 
 

I’m working on a 1999 Dodge 2500. A friend brought it to me after swapping from a v10 to a 24 valve. The engine, PCM, ECM, gauge cluster, fuel tank and engine harness came out of a wrecked 1999 dually so the year models match up. I’ve double checked all of the connections, battery cables, plugs, etc. and everything is how it should be. I was told it ran before he put it in but that it also sat for a year between it being pulled and then put into this current truck. 
 

Now, it won’t start aka it will crank but not start. Batteries are both good, cables are good, starter is good, engine turns at a good speed. I have NO codes, on the dash or with a code reader. So I started with diagnostics. 
 

Fuel system relay is functioning.
 

It has an air dog lift pump, pushing a consistent 14psi to the VP. It has a new VP44 on it as the old pump had a seized rotor and was only putting fuel to 2 injector lines. While I was changing the VP, I did a compression test and pop tested the injectors. Compression checked out. 4 of the six injectors would just pee out fuel, the other 2 would bypass to return without opening. So he pick up some new injectors. 
 

Here we are, back together with a new VP and new injectors….  Still no start. Back to diagnostics. I check ground and voltage to the plug on the back of the VP. Pin 7 has battery voltage, Pin 6 has a good ground. Plug it back in, check voltage at pin 5, no voltage at pin 5 with key on. So these three things are telling me that the VP is getting the appropriate signal and should be running. Next step is to Hotwire the pump. I Hotwire it and it fires right up and idles. So it’s an electrical issue… 
 

I understand that the MAP sensor, APPS, cam and crank pos sensors all play a role in a happy VP truck but I’m not sure where to go from here. Again, I have NO codes. Can someone point me in the direction of what else to check and how to diagnose it? Or if I over looked something? 

Edited May 21, 20222 yr by Enthusiast

I hope you're not fighting a security related issue some trucks had extra theft detection stuff. Wasn't as common in 99. Make sure the cummins bus / can bus connection hasn't been hacked up by some tuner too. Need power to red white wires at ecm and green black wire with key on.

@Great work! I’ll check it out as soon as I get back to the truck. You’re talking about #5 with key on, then #48 and #50 constant. Correct? 

Correct and ground of course. 

@Great work! Here is what I found: 

All of the ground circuits showed to be good. That’s numbers 4, 11, 12, 23, 30, 32, 40 and 49. 
 

Numbers 2, 13, and 41 showed 2.5v. 
3, 10, and 31 showed 5v.

Then 5, 48, and 50 showed battery voltage. 
 

Did I miss any? 

Seems right but the buses on the '-' side should not be hard grounds they should have some resistance to ground. Do you get a wait to start blink?

@Great work! When you turn the key on, WTS comes on for a second then goes off. 
 

I will double check the bus grounds again today, I don’t remember if they were hard grounds or if they showed the resistance. 

Edited May 22, 20222 yr by Enthusiast

Every thing seems ok