Rep Power: 0

I just bought a new battery and alternator for the car because the old alternator fried the last battery. So the mechanic put on the new parts and the the car didn't start, he changed the 80A battery fuse and it did the trick. Took the car home and left it off till later that night and the battery was completely drained. I got a jump from AAA and thought the car would be fine but the problem continued. I took the battery back and swapped for a new one, the battery still drains if left connected for 5 hours or more. I have the unplug the cables every time I'm down using the car just so I know it will start again.
Does anyone know what could be causing this

 
Rep Power: 518

Duplicate deleted, thread moved.

It appears your car has a drain on the battery when everything should have been shut off.

Did this only begin AFTER the alternator was replaced, or was this problem present before replacement?

Is anything still running after you shut the car off, like the radiator fan?
Lights stuck on (dome, trunk, etc.)?

Aftermarket radio? Amp/sub stuck on?

Does the compressor still run even though everything in the HVAC is turned off?

 
Rep Power: 0

The alternator had been draining the battery's before replacement, went through 2 battery's with the old alternator and I'm on the 2nd with the new alternator.
No, everything shuts off, I check everything to make sure its all off, I also don't have a radio in ny car so it can't be that.
The compressor actually went out last Thursday.

 
Rep Power: 518

A bad alternator that couldn't charge is different from a drain in the car that is now killing the good battery.....even though they may both result in a dead battery.

Testing draw with an ammeter would be my next step.
If I measure more than about 20mA draw then I know I have to track down a problem in the car

 
Rep Power: 0

How do you test it?
Do you have any ideas of what might be draining it?

 
Rep Power: 518

....
You may think everything is shut off, but the correct tools will tell exactly how much current is being consumed (drained) from the battery.

Once it is verified there is something wrong (excess drain), the next steps would be tracking it down.

No, but I know how to figure it out.




You say this car has been killing batteries since before you replaced the alternator...... so was the alternator actually bad or was it just a guess?

 
Rep Power: 0

Yeah I had the alternator tested before buying a new one and it was bad, it was sending to many volts to the battery.

 
Rep Power: 0

Do you think that there could be a problem with the way the new alternator was put on? Or what that not play a factor?

 
Rep Power: 518

Ok, then someone needs to confirm there's a drain on the battery after the car is turned off, and track it down.



Wild guess, no special tools: Something consuming enough power to kill a battery in 5 hours should be producing some heat.

Let car sit overnight so everything is cooled off....
connect battery in the morning....
do NOT start the engine, do not turn the key on, don't touch anything else......
wait 30 minutes or so.....
feel the alternator housing....
If it is hot, there's a problem there (may be a junk parts store reman)
(this may not work well if it's frigid out, it does work well at around 60-70 degrees F)

 
Rep Power: 0

Yeah, I'm gonna go to the mechanic tomorrow and have them take a look at it.
Is the alternator housing the only thing that would heat up or should I check out the whole engine to find a hotspot?

 
Rep Power: 518

The alternator and starter are about the only things on the engine that I can think of that are always connected to a constant power source.
The alternator was only a guess....and I've seen it a few times.

The compressor clutch could get powered up if its relay sticks on, that's a somewhat common issue in newer cars. You might check if that is warm as well.


There are plenty of other circuits in the rest of the car that have constant power supplied too, so there are lots of possibilities.


Got a thermal imager? LOL
Brake lights stuck on?

 
Rep Power: 0

start pulling fuses until it stops draing.

 
Rep Power: 222

you revived a 2 year old thread for that?

 
Rep Power: 367

he was trying to help, so fine for me