I have a 2001 Dodge Ram van 3500 5.9 magnum motor that I am installing in another vehicle. I am unable to get the engine to turn with starter relay installed. The brown and yellow neutral switch shows as grounded,the red wire shows as live when ignition is turned on and the yellow wire goes live when key is turned. Overriding by connecting the red and brown wires shows that the starter cranks. However with the starter relay installed it will not turn the starter. I wonder if there is an immobilization device somewhere. I found a disc shaped switch under the battery and am not sure what this is for. Any thoughts?

 

Check Fuse 14, 30 amp, in the IPM. It is probably blown if it won't start with the relay installed. Install the relay and replace the fuse.


The device under the battery monitors the battery temperature.