What year TJ do you have? If it's any year but 99 to 00, the Jeep can generate is own diagnostic trouble codes by turning the ignition switch on-off-on three times within five seconds. Leave the key in the On position and wait, several seconds after the last on-off-on, any stored diagnostic codes will begin displaying in the odometer. Write them down as they display and tell us what they are. We'll give you the right list of codes to decode them with.