Here's a breakdown of the common scenarios:
* No Full-Time 4WD Option: Many Jeep Wranglers, especially older models and some trim levels, *do not* have a full-time 4WD option. They only have part-time 4WD (2H, 4H, 4L). Attempting to drive in 4H on dry pavement can cause drivetrain damage.
* Command-Trac (Part-Time): This is a common part-time system. It has 2H (2-wheel drive high), 4H (4-wheel drive high), and 4L (4-wheel drive low). There's no full-time 4WD setting.
* Selec-Trac (Part-Time with Full-Time Option - Usually Automatic): Selec-Trac *offers* a full-time mode, but it's usually automatically engaged and disengaged based on wheel speed sensors. You typically select a "full-time" or "auto" setting, and the system manages the power distribution. You might not explicitly "engage" it, but rather select the driving mode.
* Rock-Trac (Part-Time): This is a more rugged, part-time system like Command-Trac, again, without a full-time 4WD option.
To know how to engage your Wrangler's 4WD (if it even has a full-time option):
1. Consult your owner's manual: This is the definitive source. The manual will clearly outline the transfer case type and how to use its various settings.
2. Look at the transfer case shifter: The shifter will have markings (2H, 4H, 4L, Auto, Full-Time, etc.). This will give you a visual clue about the available modes.
3. Identify your transfer case: The specific transfer case (e.g., NV241, NV242, etc.) can often be found on a sticker under the hood or in the owner's manual. Knowing the model helps to find specific instructions online.
In short: Without knowing the year and model of your Jeep Wrangler and its transfer case, it's impossible to give precise instructions on engaging full-time 4WD. Always refer to your owner's manual. Driving in an inappropriate 4WD mode can seriously damage your vehicle's drivetrain.
