4x4 Not working

[mustangsally1225]

I have a 2002 ford explorer. My 4x4 high light started to blink 8 times every couple minutes. I was able to engage the 4x4 at the time with no problem. The truck started to engage in 4x4 high by itself on dry pavement. It would last for about 2 minutes and go back to 2 wheel drive. Now I have no 4x4 at all unless it engages by itself on dry pavement. I checked the ground wire on the shift motor and its fine. I did replace the 4x4 control module and the lights are still flashing with no 4x4. Any ideas on what might be the problem

 

[aboyum]

my 96 explorer xlt does the same thing had it to the dealer more times then the wallet can handle everything works fine they changed just about everything but the lights still flashes I fix it myself only thing i could do took out the bulb

 

[drdoom]

mustangsally, what is the condition of your tires? Are they a matching set, including tread wear? Check the fuses also. I have heard of the sensors getting dirty.
Also have you tried disconnecting the battery for a while?
You could take it in to have the codes read, then you would know what's up.