01 2500hd not going into 4 wd

[RepoKing15]

I have an 01 2500hd.  When I push the 4x4 button it switches to 4x4 then flashes 5 or 6 times then returns to 2 wd. At no time does the encoder motor make a sound. 

Within the last month the service 4x4 did appear on message center. At that time I had to turn off truck,  turn to on...push  button and then would engage.  I'd  start truck and be fine. Now not so much. Encoder was changed .....still nothing.  Checked ATC fuse under hood and 4x4 fuse in side of dash....both good. 

When you push button does the encoder tell the actuator in front across to engage or vise versa ?  Didn't have scanned. I've been told that a bad actuator will do the same thing.  Also told the module for encoder under dash. 

Need help....snow storm tomorrow and I plow .....

[Formulabruce]

Could be cold solder joints in the 4x4 switch assembly.

 Probably easy to follow video on you tube.

Re-solder all the connections on the back of the small circuit board.

 just hit it with a hot solder iron for about 3 seconds. Put the connector back on and test before you install

 This could be a near FREE  and fast Fix.

[RepoKing15]

Thanks. Will try anything at this point.