I have used my 4-wheel drive during the last ice/snow storm. At first, the part time?

light came on when it was in 4HI, as it should. After using it, however, the light came on when it was back in 2 wheel and turned off in 4HI. I tried to get up my steep driveway while the light was on but in 2 wheel position, and I was unable to do so. When I placed it in the 4HI position, even tho the PART TIME light went off, I was able to navigate my driveway easily. My concern is that the lights are no longer functioning properly. Am I correct, or is my car actually still engaged in 4HI even tho the gear is is 2 wheel position?|||You would likely get a better and more correct answer asking this under the car and transportation section under repairs.