Reasons Why A Jeep Wrangler May Not Start (Solution Given)

When you hop in your Jeep Wrangler, turn the key, and it will not start you are likely to get a sinking feeling in the pit of your stomach. I get a lot of questions from friends and associates about why their Wranglers are not starting as they should.

For the most part, a Jeep Wrangler that will not start is likely to have a battery issue.

Let’s take the time and look at some of the most common issues that prevent these automobiles from firing up the minute you turn the key.

Common Reasons a Jeep Wrangler Fails to Start

Jeep wrangler battery

If your Wrangler does not start when you turn the key you are most likely looking at a loss of power situation. The reasons listed below are frequently the cause of an engine not starting.


The most frequent reason why a vehicle will not start is the battery. The battery supplies the power to the engine and when the electrical power supply is interrupted or reduced then the engine will not start.

If you leave a car door open, or you leave the headlights on during the night you main drain the battery of power. The result will be a vehicle that does not start.

Other Common Reasons for A Dead Battery

  • If the temperature is extremely cold outside your battery can be drained. This can also happen if it is extremely hot outside.
  • Corrosion builds up on the battery connections
  • Interior lights left on
  • Problems with the alternator
  • A crack in the battery
  • The car has not been cranked in a long time
  • Old age


You can jump-start the battery using battery cables and another vehicle, or using one of the quick start devices. You can also connect a battery charger and charge the battery up.

If you cannot jump-start the vehicle you may want to consider purchasing a new battery and replacing the old one. When you buy a new battery take the old one in to trade in as a core and you will save a few bucks on the purchase.

Fuel Problems

Low Fuel gauge showing fuel dashboard

One of the first things you might want to check if your vehicle does not crank is the amount of fuel you have in it. If the fuel is very low and the vehicle is parked on a slight slope there is a chance that you are not getting enough fuel to the engine to make the automobile start.

What Gear is The Vehicle In?

If your vehicle is in the wrong gear that is a good chance that it will not start. Check your gear shift and make sure that your vehicle is in the park or neutral and then try again to crank it.


Your alternator is what makes your battery recharge while you are driving. If your alternator goes bad then it does not charge the battery and you wind up with a vehicle that does not crank when you want it to. 

If your alternator is the reason why your vehicle is not cranking there is a good chance that you have seen the warning signs in the last week or two.

Warning Signs of An Alternator That is Going Out

  • Your headlights may have seemed to be not as bright in the past few days. You may also have seen headlights that were really bright or your lights may have flickered.
  • Your electronics in your car may have been slow to respond or they may have been acting up
  • Your vehicle may have been stalling out

What To Do

If you suspect the alternator in the vehicle is bad you are going to need to replace it. You can check the voltage of the alternator with a multimeter if you have one, or you can stop at some of the big chain auto parts stores and they will check your alternator for you.


One reason why your car may not start is that the starter may have gone bad. If the problem is your starter there is a good chance that over the last few weeks you have seen some warning signs.

Warning signs that your starter is going out

Your vehicle may have been struggling to crank the last few times you tried to start it.

  • When starting the car you might have heard strange grinding noises.
  • Your lights and other electric powered accessories work but the engine will not start
  • When you turn the key to the ignition you hear a clicking sound
  • Your engine whirs but it do not want to engage

What to do

If the starter in the vehicle wears out you are going to have to replace it. You might remove it and take it to be rebuilt, but for most people, their only option is to have the starter replaced.

The good thing about replacing a starter is that they are not super expensive to replace. For less than $400 you should be able to pay for the parts and labor to replace your starter.

Frequently Asked Questions

How Long Should A Jeep Wrangler Alternator Last?

These parts will be fully functional for 7 years or around 100,000 miles.

How Much Does A New Alternator for A Jeep Wrangler Cost?

An alternator for a Jeep Wrangler may cost between $345 and $500 with another one hundred or so for installation.

How Much Does A New Battery for A Jeep Wrangler Cost?

A replacement battery may cost you as little as $150 or as much as $240 depending on your location.

Final Thoughts

Having a vehicle that will not crank is absolutely frustrating. When this does happen to you try to remain calm and investigate all of the small things that can cause this to happen before you call a tow truck to have it hauled to the repair shop. One of the quick start devices that charge your battery or give you a jump without another car is a wise investment, especially if you live in a rural or remote location.

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