2000 isuzu rodeo shift indicator problems

hope some one here have some ideas as to where to look for problem.
truck keeps blowing the nuteral safty switch (ie the at shift indicator).
replaced the computer ( for another problem with egr codes)
replaced the shift indicator mod. (under the center console)
check wires fro short to gront or power or to each other and no luck but still blowes that switch in less then 3 mins. sounds like a short but no luck in finding it.
any help would be great thanks

http://www.walkerdowney.com/ryanendres//isuzu/#faq59

Your range selector that is bolted to the side of the transmission is probably causing your issue. You can open it up and clean it out ... or your best bet is to buy a new one for under a hundred bucks....

That's what I keep replaceing. I also just found out from the previous owner that the trans was worked on then this problem started shorlty after.

There has to be a wire pinched somewhere that is shorting it out. i would assume the wire is somewhere by the tranny since it has been out of the truck.