1999 chevy silverado service 4 wheel drive light

I had a similar problem with the Service 4 Wheel Drive light which came on intermittently then became more consistent in the message center display. It would go into 4 wheel drive if the message center did not display the Service 4 Wheel Drive message in the message center, but not when the message was displayed. I found the transfer case switch module in the dash was defective, and it has been working with no other problems for three years.

From Late '98 to '07 they had issues with the pumps rubbing a hole in the rear transfer case housing. I got an aftermarket upgraded pump kit to fix the problem before it became "Really Expensive issue" $900+ for my dad., The kit was $175 from Merchant-automotive.com They have geat instructions on their website and are very helpfull over the phone. According to them, my dad should be transfer case worry free for 100,000+ miles(those transfer cases do have clutches that may need to eventually be replaced, but merchant automotive has those too!) Thank you for helping us in our time of need, and I hope others are able to fix this problem before it becomes a expensive issue!!