Discovery 1 turns over but won't start
Immobilizer is on the fender wall passenger side. It's between the evap canister and the computer. Check all the fuses. Don't start changing a bunch of parts until you have ruled out the obvious. I just went through this same thing. Do you have a scan tool to check the codes?
As for the installation of the crank sensor i believe i installed it correctly. Disconnected the battery first. Then removed the old crank sensor. Then installed the new crank sensor in the reverse order of the removal. Multiplug is connected all that good stuff.
What does it look like? Got a pic? If no pic, please describe it.


