I have a 2003 Neon and the Battery lights stays on constantly.

I just had to replace the tensioner pulley assembly because the pulley was shot but before this i replaced the alternator 4 or 5 times trying different vendors. every time the light just stays on. The battery has been replace a few times as well due to bad cells.

took it to autozone and they tested the alternator saying that it was good but not charging the battery. All of the connections are tight and clean.

I have heard the voltage regulator is in the PCM on this model. Is this correct?
Is there anything else that could be causing the battery light to stay on all the time?

I need some help my civic is dying and this neon is my last hope :/

 

Do you have a battery temperature sensor? If you do, and it's not properly placed or hooked up, the battery light will stay on and the battery will not charge properly.

 

I am new to neons where would the battery temp sensor be?

 

I have been reading about the battery temp sensor and this could be it...

i replaced the battery a long time ago and not thinking i tossed the battery blanket so that sesnor would just be hanging out somewhere...

makes me wish i had the car with me to look.

 

Turns out it was the BTS.

I have never heard of such a thing before.

Now i Have to replace the water pump

 

Haven't been looking in this area, sorry. Yeah, it's a crap sensor that was only on '03/'04 cars. As long as it is close to the battery (with or without the wrap), it should be fine as I'm told.

 

Thank you, it was the battery temp sensor. I wish i found this site sooner it would have saved a lot of money and time.

mine was actually missing from its socket. i managed to get one through the dealership and now the light is on.

 

Hey all, my neon died the other day and wouldn't start. The instrument panel, radio and lights went bezerk once it died. I replaced the altenator, then the battery. It ran for most the day, and then died again. I asssumed the altenator didnt charge the battery and was faulty, so i swapped the altenator for anoither. All the time too, the battery light has been on, that seemed odd. frustrarted, i found this site and someone suggested the battery sensor! I notice mine was not plugged in, so i did so and the light went off. My question is... can something so simple regulate the car so much that this problem will end. What is the role of this battery sensor?

 

According to Dodge, yes, that sensor is what allows the car to properly charge the battery and tells it how much to charge the battery at any given time by the temperature of the battery. Stupid? Yes. Do you need it to work though? Yes.