Why does my light stay on in 2 wheeldrive but when I put it in 4 hi or 4 low it goes off.. I've searched couldnt find anything unless I missed it...2003 2500 5.7

 

Hmm, strange, sounds like a sensor to me. try putting it in 4x4 them turn it off while its loccked in give it a second then start it back up and put it 2wd and turn the truck off again and give it a second then start it back up and see if that works.

 

I also googled it, someone else had a similar issue and they replaced the neutral safety switch to fix it.

 

Something else I found, might want to see if you can find this or even have it: There is a vacuum/switch on the top of the transfer case. has 4 vacuum lines on it arranged in a square. It will go on four different ways. 2 of them will give you a correctly working 4wd with light. and the other 2 seem to give you a correctly working 4wd with an opposite light.

Possible vacuum leak??

 

Thanks for the info.. I'll have to crawl under her this weekend and start checking lines