Sorry to ask another 4x4 question, but don't know which way to go next. Last winter durning the last snow storm I jumped in my truck turned on my 4 wheel drive and got nothing, no lights and din't engauge. I used my 4 wheel drive all winter long Then this spring all of a sudden the 4 wheel drive started working again. This past weekend I used my 4 wheel drive to pull down to the barn and it worked fine. 1 hour later I backed in to our hunting property spun my wheels in 2wd so I turned on 4 wheel drive and nothing again lights or 4x4. I have tried all this week and still nothing until tonight I ran to town figured I would just try again and it is working again. I replaced the IWE Solenoid last winter and it didn't change anything. I did notice sand was in the vacumn lines when I took the old one off.

Please help