I agree, the neutral safety/backup light/gear selector switch is responsible for many problems. You can access the switch by first taking the S/E/M or A/M selector on the left of the shifter out ( it prys out and then the connector disconnects) and then releasing the shifter handle (be careful to hold the shifter trigger up or depressed, I use duct tape or the plastic rod will fall out and ypu will have to reatatch (no big deal unless this is afirst time)to the pin behind the trigger. The consloe wood then can be pried out starting at front corner and then you will see the white platic shfter assembly in the shifter cavity and next to shift rod. Easier to go to www.nmia.com/~dgnrg/page_2.htm
which is Don Gales How to, with picture and text.