95 Camery - electrical problem

[kevwit]

Since March 2005 I have had problems with my camery. It has been killing batteries to the point where it actually kills the engine. It seems to only happen during winter (due to heater or lights?) as it ran fine all summer.

My battery and alternator are under warrenty. I have gotten about 7 new batteries, electrical tested it 3 or 4 times, replaced the positive and negative battery cables (seemed to help for a couple weeks), replaced the alternator, etc.

I thought it was fixed and just this morning found out the battery was dead again!!

Any ideas?

[Mike Gerber]

If you have had the alternator and battery checked and replaced repeately, then the next step would be to check for a "dark current" draw. This is the current that the car is using while the engine is off. It's mainly things like keeping the ECU's memory and your radio presets in memory. You may have an excessive draw. To do this you will need a DVM (digital volt/ohmeter). Remove the negative battery cable. Set the meter to a milleamp setting and touch one of the leads to the battery post and the other to the battery cable. The reading should be around 20 milleamps or less. If it is much higher than this, you have an excessive dark current draw. That is what's killing your battery. To find out what circuit the excessive draw is on, pull the fuses one at a time and then go back and check the meter reading again. When the excessive draw has been eliminated by pulling a particular fuse, you have isolated the draw to the items protected by that fuse. Now you can go and check out those items individually. Many times an excessive dark current draw can be traced back to a defective aftermarket alarm system. Do you have an aftermarket alarm system installed on your car?

Good luck.

Mike

[kevwit]

Originally Posted by Mike Gerber

If you have had the alternator and battery checked and replaced repeately, then the next step would be to check for a "dark current" draw. This is the current that the car is using while the engine is off. It's mainly things like keeping the ECU's memory and your radio presets in memory. You may have an excessive draw. To do this you will need a DVM (digital volt/ohmeter). Remove the negative battery cable. Set the meter to a milleamp setting and touch one of the leads to the battery post and the other to the battery cable. The reading should be around 20 milleamps or less. If it is much higher than this, you have an excessive dark current draw. That is what's killing your battery. To find out what circuit the excessive draw is on, pull the fuses one at a time and then go back and check the meter reading again. When the excessive draw has been eliminated by pulling a particular fuse, you have isolated the draw to the items protected by that fuse. Now you can go and check out those items individually. Many times an excessive dark current draw can be traced back to a defective aftermarket alarm system. Do you have an aftermarket alarm system installed on your car?

Good luck.

Mike

I have a bulldog auto-start and alarm system. Thanks for the tip. Someone else said they have seen where the starter could do this also. I will try this out also and see what I can find out.