2006 Dodge Ram 3500 5.9 will not start from key- but will start with key turned to on position and B+ jumper to the Yellow/Gray Starter lead wire under the hood. When I try to start with the key I do hear the starter relay clicking but no 12v reaches the starter lead that I am jumping to start thevehicle. Tried another relay and same thing. It is an automatic transmission so I also tried to start in Neutral and wiggle the shifter and still no bueno! I check continuity from the green/yellow wire on the ignition switch to the relay and that is good and same thing for the yellow/gray wire from the relay to the starter. Some where power is not being allowed to pass through the wires. Worked fine o day- Parked it- then wouldn't start- thenn all of a sudden it fired up- ran for two days with starting and stopping it several times and then again- No start and has now been this way for 9 days- I have made a push button switch so I can start thetruck from in the cab with the jumper but I rather correct the situation-I am jumping to power to the yellow/gray wire that goes directly to the starter solinoid- the clicking soud I hear is from the starter relay which is mounted next to the fuse box and driver side battery. nothing is actually getting to the yellow/gray wire which is why I am needing to jump it to a power source for the truck to start. If it was a bad key then it would shut down- not continue to run. I also tried using the remote start and it also is not working-

 

Check for a short on the starter trigger wire. It will chaff on the motor mount

 

Nope. Thats the wire im jumping to start the truck right now

 

Might be the neutral safety switch on the transmission.

 

Disconnect both batteries for a few minutes and see if that will work. Is it a factory remote start? If not, disconnect it. They can cause issues.