2017 Ram Crank but no Start

[Nassini]

I have a 2017 Ram 2500 Power Wagon 6.4L and have recently expereinced a crank no start issue that I can not figure out. I orginally thought it was the fuel pump relay and installed a bypass. This worked for several weeks and then started working intermittently. It is no longer working. Thinking it was a fuel pump issue, I dropped the tank and started testing the pump and the plug. When i hook the pump to an independent battery the pump works as it should. I tested the ohms on the pump and it is showing 0.9 ohms. I have 12 volts to the plug but once i hooked the pump to the multimeter and to the plug the voltage drops as soon as the key is turned on. I have tried this with the factory relay (tested good on scan tool) and with the bypass installed. I purchased a new pump so I could do some additional testing but i am getting the same results. Does anyone have any ideas what the issue could be or what to test next? I have searched google and multiple forums but I can't seem to find someone that is having similiar issues or if they had something similiar they did not reply with what caused/fixed the issue. Thank you in advance.

 

[Burla]

You bypassed TIPM or Win module? When you hooked old pump to independent battery it worked as new one did?

 

[Nassini]

I hooked the bypass to the number 90 fuse for the cigarette lighter on battery and then to the number 70 fuse for the fuel pump. If i am not mistaken this bypasses the fuel pump relay.

Yes, when i hooked the old pump to indepenent battery using the outside most terminals it fired up and started to pump fuel. I did not test the fuel pressure (pumped into 5 gallon jug) but it appeared to be good pressure. The new fuel pump was only tested to see if it worked. I didn't want to submerge it fuel and risk not being able to return it.

 

[Rammer25]

Any update on this? Interested as I have the same crank but no start issue. Only difference is the night before the no start, while driving, I used my horn to scare off some deer. The horn changed tone from normal to baby civic. Next morning, ran real rough on warm up. Then stalled and hasn't ran since. Cranks fine. Tested tipm as best i could though it is too cold for me to bypass it right now. I'm thinking with the added horn issue, its a ground wire issue possibly.
2019 Ram 1500, 5.7 hemi.

 

[Nassini]

I have temporarily fixed it by hard wiring the fuel pump to a switch on my auxbeam controller. I have a feeling its a ground but I have needed the truck for work and haven't had time to go through and check everything.

 

[Flstss]

I have temporarily fixed it by hard wiring the fuel pump to a switch on my auxbeam controller. I have a feeling its a ground but I have needed the truck for work and haven't had time to go through and check everything.

Any updates on if you found anything I'm now having a similar situation