Car battery keeps dying - Toyota Nation Forum : Toyota Car and Truck Forums

Tukimoshi · 02-26-2011, 01:00 AM

Hey guys,

Today my 1990 Corolla battery has died twice. I noticed the last time I parked that when I turned off my car, the fan suddenly started blasting. I looked at the label on the fan and it said "May turn on/off regardless if car is on" and I looked online and it said the fan may run while the car is off to cool the car.

However, I just went outside to start my car and it's completely dead again. It's weird because this has only started happening today and it's colder out than usual (We have snow which is very rare for here)

Anyone got any ideas? Now I need a jump-start but it's 11pm at night (Wanted to go out to get some food, it's late and I'm starving)

***plyr503*** · 02-26-2011, 01:36 AM

cold weather can be hard on batteries, when did you last replace this one? Might be a good idea to have a charging system checkup...alternator, hell starter too

***SCT*** · 02-26-2011, 03:17 AM

My fan never stayed running when the key is off. Only when it's on.

+1, I get a new battery too.

Tukimoshi · 02-26-2011, 10:43 AM

Quote:

Originally Posted by plyr503

cold weather can be hard on batteries, when did you last replace this one? Might be a good idea to have a charging system checkup...alternator, hell starter too

I bought the car used and have only owned it for a month or two, the battery is quite new however. I believe the alternator was just replaced in it before I got it too. The previous owner of the car put $3000 into it before giving it away to my High School Auto-Shop so I nabbed it for only $500.

Oh, and it's not extremely cold weather. It's about 0C or -1 C. (32F or 30.2F)

Flashmn · 02-26-2011, 11:48 AM

Short circuit somewhere and its bleeding current. Take off the negative battery terminal and get a multimeter, put it to 20Amp mode and put the positive probe to the negative battery cable and the negative probe to the negative battery terminal and see how much it reads. Whatever you do dont put the amp meter between the positive and negative battery terminals, you'll see sparks.

Tukimoshi · 02-26-2011, 10:54 PM

Quote:

Originally Posted by Flashmn

Short circuit somewhere and its bleeding current. Take off the negative battery terminal and get a multimeter, put it to 20Amp mode and put the positive probe to the negative battery cable and the negative probe to the negative battery terminal and see how much it reads. Whatever you do dont put the amp meter between the positive and negative battery terminals, you'll see sparks.

I ended up disconnecting the rad fans and now my car is running fine. The battery and alternator are fine (As I said I thought earlier) and it was the radiator fans running whenever the car is off. I'm not sure currently why the fans would turn on only when the car is off, and my car isn't over-heating so it's not a lack of coolant or anything.

90 GP · 02-27-2011, 07:32 AM

Sounds like a bad relay or sensor that shuts off fans is keeping them running and running down battery. You need to have it working correctly to avoid overheating and causing engine/head gasket failure. If you want to trace circuit here is wiring diagram link. Look at fig 4 for Radiator Fan Relay.

http://opc.mr2oc.com/online_parts_ca...CorollaFWD.pdf