If the battery light has come on in your second-generation Dodge Neon (1999-2005), a few things need to be checked to find the problem.
This is not meant to give a detailed guide but a basic overview of what needs to be checked.
Possible Causes of a Dodge Neon Battery Light
- Voltage Regulator
- Battery Temperature Sensor
The first thing that should be checked is the alternator. If you have a multimeter, it can be checked by placing the leads on the terminal and finding the voltage when the car is running and when it is off.
When the car is off, the voltage should be 12-13 volts.
With it running, it should be between 14-16 volts.
The voltage will vary between those numbers depending on the shape the battery is in and what else is on in the car, such as the radio, air conditioning, and so on.
If the voltage doesn’t go up above 14 volts when it is running, the Neon is not charging correctly.
This usually means a bad alternator but could also be a bad connection or computer voltage regulator problem.
An alternator can be taken out of the Neon and taken to an auto parts store such as AutoZone, which will test it for free and see if it is bad or good.
With the car Off and using a multimeter the battery should read at least 12 volts. If it is lower than 12 volts, it may still be good but simply hasn’t been charged.
A battery charger can be used to charge the battery. If it holds a charge, then it is good; if it doesn’t hold a charge, it needs to be replaced.
There are not a lot of wires going to an alternator.
One big red wire will go to the starter, which connects to the battery, and the smaller wires will go to the voltage regulator.
Checking the wires for any cuts, breaks, or bad connections should be made.
There is also a fusible link located near the starter that can possibly burn out.
All wiring connections can be tested with a meter set to read continuity.
The voltage regulator on the second-gen Dodge Neon is built into the car’s computer (PCM).
When a voltage regulator fails, it will cause the voltage to vary wildly, which it should not do.
If this is found to be the problem, then it can cause other problems since the voltage can go high above normal. The fusible link may blow if the voltage goes too high and would also need to be replaced.
The Second-generation Dodge Neon has a battery temperature sensor that is located on the shroud that sits around the battery.
If it fails, it will cause the battery light on the dashboard to come on.
They are easily replaced if faulty.
Be sure to test everything else before replacing the temperature sensor.
Also, a battery temperature sensor is a dealer-only option, so most parts stores will not carry them.
Luckily they can be bought online on Amazon or eBay.
Just wanted to update this a little bit for you. Another reason that battery light may come on, especially if you’ve just done work on the car that involved moving/removing the air cleaner box, is that the Intake Air Temperature sensor may be either bad, or have a dirty or mismatched connection. I had this happen yesterday, battery light came on, with the engine light, had a P1193 air intake sensor code. This was after I had removed the intake box, battery, and battery tray, in order to replace the bushings on my transmission linkage.
I was entirely at a loss, until I read on a forum about the fact that the IAT sensor can in fact throw a battery light/engine light up, because in some model Neons, the IAT is in fact also doubling as the battery temperature sensor, due to the close proximity to the battery area. When this sensor is not working correctly, the PCM is unable to determine the correct voltage to charge the battery, which it bases on the ambient air temperature coming from outside, and as such it is forced to use a default voltage and then throws the code and light up.
I pulled the sensor out, pushed it back in, shook it around a bit, and it worked. I was shocked. Anyways, this is good info for people to know.