Why is the Battery in My 2003 Chrysler PT Cruiser Continually Going Dead?

Written by

Mia Bevacqua, ASE Certified Master Automobile Technician

Automotive Subject Matter Expert at CarParts.com

Updated on September 25th, 2023

Reading Time: 3 minutes
Summary
  • If the car battery of your 2003 Chrysler PT Cruiser is always dying, there’s a good chance your vehicle has a parasitic drain.
  • There are many potential causes for a parasitic drain such as trunk light bulbs being left on or onboard computers failing to shut off.
  • Aftermarket devices plugged into the vehicle are also common causes for parasitic drain.

Q: I have a 2003 Chrysler PT Cruiser with a 2.4L engine. The battery will not hold a charge for more than 24 hours.

The battery has been replaced twice, along with the alternator and battery cables. What could be causing the battery to keep going dead?

– Maggie Zimmerman from Brooklyn, Michigan

A parasitic drain on the battery means that something is staying turned on (and draining current from the battery) when the ignition is turned off.

A: Hi, Maggie. It sounds like your PT Cruiser has a parasitic drain on the battery. That means that something is staying turned on (and draining current from the battery) when the ignition is turned off. The source of the drain could be anything from a trunk light bulb staying on to an onboard computer remaining awake.

Devices added on by vehicle owners, such as phone chargers and insurance tracking units, often end up being the source of the parasitic drain. So, if you have any add-on devices installed in the car, start by unplugging those first (if possible). 

If that doesn’t solve the problem, you’ll need to find a mechanic who can track down the source of the drain by performing a parasitic drain test. The procedure involves placing an ammeter in series with (or an amp clamp around) the negative battery cable

The source of the parasitic drain could be anything from a trunk light bulb staying on to an onboard computer remaining awake.

When performing the test, the ignition should be in the “off” position with the key removed. All of the car’s doors must be closed and any underhood lights and hood switches must be disabled. The onboard computers must also be given enough time to “go to sleep” before performing the test. 

Generally, a drain of more than 50 milliamps is considered excessive. On your particular car, however, the specification is no more than 35 milliamps.

Once a drain is confirmed, most mechanics start pulling the car’s fuses one by one to determine which circuit the drain is coming from. Then they can start unplugging one device at a time within that circuit to pinpoint the drain. 

Good luck! 

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View Comments

  • Just turn your ignition switch off and the one turn back that should solve your dilemma
    If you do not the acc stay on and drains the battery
    Acc
    Lock
    Off
    On
    Start
    Silly concept 🤪 but that the way they decide it should be