Guys I’m pretty sure this topic has come up so sorry if the question is redundant.  2000 Cummins was starting fine and also idleing fine, but if I gave it and throttle the engine would shake.   Tried checking the pressure on the lift pump, 0, none at all.  Figured it was a bad lp so I dropped the tank and swapped it for a new one.  I bumped tested the new one and nothing.  Now truck will not start.  Checked my relay and swapped it out with the horn relay and truck still honks.  Please help!!!

Check the ECM plug to lift pump for voltage, it's somewhere in ecm area. If you're getting nothing then could be a bad circuit in ecm, fried because of wiring issues. WT mod and accessories noise on alternator are first things to do. Then if circuit is bad there are other ways of tapping to things with relays to get it working without spending money of fixing ecm.

Here's the diagram for wiring in a relay.  The yellow/white wire should have power when you first turn the ignition on or bump the starter. Test with a volt meter or test light.

 If the #30 terminal is jumped to #87 the fuel pump should run. 

 

I read somewhere that there is a possibility it could be the crank shaft sensor, is that possible?

Have you checked for any trouble codes? A bad crank sensor can make your truck undriveable but should not affect the fuel pump.

Only code that comes up is a p1689.  

This could be part of your problem. A wiring issue or computer issue.

 

As far as your lift pump, where did you swap the relays, in the PDC? I ask because the in tank pump most likely has the relay and the fuse for the pump on the firewall. Thats where Dodge put mine. It is possible the fuse on the pump blown also. Was the first pump running when you saw 0 psi?

The firewall relay has a small 15 amp fuse, it was blown.