As the title states I am having an issue with my 1999 1500 sport. I was pulling into a parking spot today and noticed that the 4wd light was on, but was very dim. As I came to a stop in the spot the light was completely lit and the 4wd seems to have engaged by itself. I just moved it around the spot and its seems as if it was in 4wd. I then actually put it into 4wd using the shift lever and then took it back out a few times, but the light stayed on and in 4wd. It was pouring rain so I ran into the store and got what I needed then came back out to mess with it some more. I pulled it out of the spot to see if the light was just staying on, but it was still in 4wd with the shift lever in 2wd. I then moved it farther out into the parking lot to avoid and then tried to shift it out of 4wd by putting the lever in and out, but no dice. I finally got it out by shifting the transfer case into neutral and then into 2wd. I noticed as I was driving back to my apartment, and the light would dimly light up and get brighter as I came to a stop. I couldn't feel it engage again until I had to stop for a light and as I turned the steering wheel fought me a little, the light was dimly lit and then went away as I turned and was going down the road. It has been raining all day, and I do not have a front bumper at the moment. The truck is a 99 1500 sport with the 318, I have never had this issue before, but it has not wanted to engage in 4wd before, the light would be on, but it would be in 4wd. I found a vacuum leak from the manifold and that fixed that issue. I'm hoping it has to do with the rain, but I could not find anything that matched my problem. I appreciate all of the input that you all may have.
I know there is a lot of writing above, but it was needed to accurately describe my issue.