4 wheel drive problem

[adunndome]

when i push the 4x4 button on my truck some times it just flashes and it won`t engage in to 4 wheel drive,some times it works fine.i don`t understand what`s going on .Help!!!!!

[70camaro]

What year, model, etc. are we talking about???
Check the ele. connection at the front diff.

[adunndome]

Originally Posted by 70camaro

What year, model, etc. are we talking about???
Check the ele. connection at the front diff.

It is a 1997 gmc k1500 ext.cab pickup with a 5.7 engine

[leeder70]

i know the piston on the front diff. does stick sometimes if it is not used often. i try and engage mine at least 1 time every couple of weeks