Jeep Cherokee Ignition Problemsby Richard Rowe
If there is one common denominator amongst practically all 1984 to 1996 Jeep Cherokees (XJ , ZJ, WJ and WK's alike) it is a bad ignition. Though typically robust, most Jeep Cherokees will eventually experience ignition failure, leaving otherwise happy owners stranded. These failures are usually progressive, though, offering the savvy owner plenty of opportunity to fix them before they become terminal.
Symptoms don't get more straightforward than this: The truck doesn't start. Turn the key, and everything comes on, but the driveway is absent of that Jeep rumble.
The Ignition System
When you turn the key, a number of things happen. First, the key-switch engages the vehicle's accessory systems like the radio. One click further activates the rest of the system, including the engine ignition, gauges and electric fans. Turning it further engages the momentary switch that sends power to the starter and turns the engine over.
Neutral Safety Switch
To ensure that absentminded owners don't run over the dog, all modern manufacturers use a neutral safety switch to disable the starter if the transmission is left in drive. These switches are usually in a "default-off" position, and must have current to activate the starter relay. This is the source of the Jeep's ignition issues, but is easily replaced by any mechanically competent owner.
The neutral safety switch is located on the transmission, where the shift lever attaches. Replacing it simply involves removing the attached wires, pulling out the sensor, installing the new one and adjusting it. At $229 (AutoZone) the Duralast sensor isn't the cheapest fix, but will outlast the stock sensor by a wide margin. One benefit to replacing the sensor is that the reverse light sensor is integral to the unit, so you are getting two new sensors at once. It's expensive, but it sure beats walking.
The Band-Aid Fix
Many have found that in the beginning stages of failure, it is possible to reset the switch to get home. If your Jeep fails to start, try placing it in neutral, and then starting it. This works in 80 percent of all failures, and will continue to do so for some time before a more permanent fix becomes mandatory.
The Worst Idea Ever
Some owners choose to simply bypass the neutral safety switch altogether by joining the external sensor harness wires together with a jumper wire. It does work, but will allow the truck to start in drive and reverse. Do yourself and your dog a favor: Just replace the switch and be done with it.
Richard Rowe has been writing professionally since 2007, specializing in automotive topics. He has worked as a tractor-trailer driver and mechanic, a rigger at a fire engine factory and as a race-car driver and builder. Rowe studied engineering, philosophy and American literature at Central Florida Community College.