Originally Posted by
NITROUS
You shouldn't need the old pcm unless you run in to fuel pump sending unit issues like some of the 98's and newer trucks have since they read different. I would pull the following:
1. Torx bit screw out of the C100 connector and pull connector off.
2. Pull out the 3 bolts under thfender well that hold the fuse box in place.
3. Disconnect the plugs by the A/C blower under the dash and pull the harness through the firewall under the A/C accumulator once you pull the 2 screws out.
4. Remove the battery cable to the fuse box under the hood.
5. Disconnect wiring harness on the firewall under the wiper box and cruise control module.
6. Disconnect the ground straps and pull harness with the engine.
Once this is done you can lay everything out neat and remove everything you don't need and also compare to your new harness.
This just made the swap easier and not quite so cluttered but do it the way you feel is easiest.