Help My Jeep Won't Start - Jeep Cherokee Trouble Shooting Failure to start out falls into two categories:
1) The engine is not going to turn over - the starter motor will not run
Or
2) The engine turns over but will not fire and run.
jeep grand cherokee transmissionThis information will address the initial cause. If you engine turns over but will not fire see my other article.
Start by checking battery voltage. Most Jeeps use a voltage meter about the dash. If the voltage is low - below 10 volts, look into the following:
1. Fist verify if there is an underlying cause for that battery to become discharged. Were the lights left on? Doors left open or other power draining accessory left on? In that case, shut off the drain and make use of jumper cables to start employing a charged battery from your different vehicle.
2. If there is no excess power drain, check the condition with the battery cables. Eliminate the cables from the battery posts and clean the contacts. Also look at the connection with the ground cable for the vehicle body.
3. If the battery cables are neat and making good contact and also the voltage continues to be low, verify that the alternator is working correctly.
jeep grand cherokee transmission4. If the battery continues to don't start your Jeep, replace the battery.
If the battery voltage is typical nevertheless the engine still is not going to revenues, the most common cause is among the safety interlocks. By using an automatic transmission there is a Neutral Safety Switch (NSS) that only allows the engine to begin in neutral or park. The contacts in the NSS can corrode and make the switch to malfunction. Move the shifter back and forth while turning the key to start out. The motion will cross a spot on the switch that also works. The NSS can be disassembled and cleaned or just substituted for a brand new unit.
In the event the NSS is working properly but the starter still won't turn, you might have a defective starter or starter solenoid. The starter and solenoid are replaced being a unit on the XJ Cherokees. However before selecting as replacement starter, look into the wiring connection around the starter and the trigger wire towards the solenoid. Often these connections can be loose or dirty as a result of rigors of dirt driving. Many people have reported that starters can be disassembled and cleaned to correct problems but I have not tried this procedure.