My 2003 Discovery will not start. The problem started months ago by my truck sounding labored when I started it sometimes. When this happened and I turned the key off then back on again it fired up as usual. One day it seiced to start all together. I purchased a new battery when it was slow to start and a new started when it wouldn't start at all. Neither seems to be the problem. Any ideas? There is power to the starter, except for the lead wire (which still has no power even when key is in the start position). The M and S lights blink on the dash and the security light is blinking extremely fast.

Thanks for the help

 

Crank position sensor

 

Didn't up being crank sensor but a blown fuse to the computer. Not sure where its located but cost $295 to have a shop fix!