4x4 will not stay engaged
 

I have a '99 Chevy Blazer that when I put the 4x4 in 4hi or Auto 4x4 the light flashes until I put in Reverse then when I go into Drive it flashes.

Also noticed sometimes when I come to a stop the light comes on solid then as soon as I move it flashes.

I seen on some other sites that the electronic module connector might be corroded, I took it off and clean it still doing the same thing.

does anybody out there know what this may be?

Hello and welcome to the forum. You should post your question in the "second generation" section of the form. You'll get a much better responce if you do. This section is to introduce yourself to the forum. My Blazer is 2wd so I can't help you but good luck with it and welcome again.