Chevrolet Repair: 95 S-10 Blazer 4x4 intermittant shift, weather pack, ign

Question
shifting in all ranges, some days it will work and others it wont (three button on dash) When it doesn't work I reset the TCCM ( #3 fuse out Ign on/off 5 times) it will start to work again for up to a week.  Sometimes when I start it the lights will be on and other times they wont.  when its working it shifts great and acts normal.  Should I suspect everthing after the TCCM is good and replace the TCCM or should I suspect the Encoder motor?

Answer
had the same problem with my 95 jimmy. when it rained, or snowed, 4 wheel drive didnt work, dry, worked fine. found a wire running down to the encoder exposed and grounding out everytime it got wet. also, check the weather pack on the plug at the encoder. if its old, it may not be holding the water back. also, pull the plug off and inspect the connectors for corrosion. if all this is ok, you may have a bad encoder.