Why would the 4wd light not come after changing it into 4wd?

If the 4WD light doesn't come on after switching to 4WD, it could indicate a few issues. There might be a problem with the transfer case or its control module, preventing the system from engaging properly. Additionally, issues with the 4WD indicator switch or electrical connections could also cause the light to remain off. It's advisable to check for any diagnostic trouble codes to identify the exact issue.