Parasitic battery drain - please help
 

I have a random battery drain issue I am trying to fix.

The car can sit, sometimes for days and start right up. Other times I park it and the battery is down to 8 volts in twenty minutes.

Here is what I have checked.
1. It is a new battery, plus I have tried three other batteries
2. Amp meter in circuit sometimes shows .2 amps to almost nothing.
3. With the main lead to the engine bay disconnected the car does not go flat.
4. removed and tested the alternator - It passed. Reinstalled.
5. figured it was the starter, replaced.
6 reassembled car moved car, - battery flat after 30 minutes.

Now with the car parked, key out, doors closed, lights off the car is pulling 3.8 amps.

Grrrrrrrrrrrrrrrr..

Have you pulled fuses one-by-one to find out what circuit is drawing power?

Check individual circuits, did you put a new radio in or something? Clear any codes, see if that changes anything

I'm in on this. My batt goes down fast while it sits.

Updates
 

No, No new radio etc.

I pulled all fuses the other day to find nothing, however I tried again today
When I pulled C3, (central Locking etc) draw stopped.

When I look at the circuit diagram for Central Locks Alarm System, wow, where does current enter that diagram?.

No clue what it could be now?

Thanks for your input

Immobilizer drawing power?

Seems like it
 

Certainly seems like it, heard of it before?

Immob drawing power....
 

check the ground at Immiobilizer...

if your lucky it's that.

otherwise, water intrusion into box?
any other "symptoms"/issues?

luck

I'd start by making sure the ignition coil isn't monkey'd up. I had an issue once where the interior light didn't go out after you locked the car.


the other thing to check is the trunk and frunk lights. Best way to do that is to put a child in there (with a flash light) and see if it gets dark. LOL, I am kidding. Just drop your phone in and record some video.


/

Funny thing, my battery completely died on Friday when I went to get a Environmental test done on my car... the battery would not take a charge at all, not even a boost could start it. Even tried to jump start the beast and no go.... ended up buying a brand new battery again for the car. Seems like the battery in my car lasts only 5 years max. Not sure what is happening or if that's just normal....

Do you live in a hotter climate? Batteries seem to hold out longer in colder weather. My truck has lasted 7+ years on a single battery, but it was also always outside in the snow

It may depend on what quality battery you get, I consistently get 6 Years fro "premium" part store batteries. The last Die Hard Platinum on my truck went 9 Years !

A typical car battery has about a 40 amp hour rating. If your battery is fully charged, a 3.8A load would take at least several hours to drain the battery. To drain it in 20 minutes you would need current drain in the 40A ballpark, which would more than likely create heat/smoke/melted wires.

I would look into the charging system to make sure the battery is getting fully charged. Check the voltage on the battery with the engine running. Also, try turning on lights & wipers with engine running to make sure the voltage holds.
It is possible to have a weak alternator that can put out sufficient voltage with a small current load, but will drop off with heavier load such as headlights.

Cornontherob - I am up in Canada so not going to get much colder than here... however, I do take the battery indoors and store it on a charger... the battery brand is more economy priced from what I can see... not sure if that would do it or not. How long should battery for our car last ??

What is the charger you describe ... charger or maintainer?
Volts when battery is removed?
Volts when engine is at 3k revs?
Battery ever been load tested?

It is possible for a new battery to be bad. Also common for a voltage regulator to be bad.

I found my battery draining parked in my garage overnight. Turned out to be a simple fix. Don't leave the key in the ignition. It was turned off but the battery would drain. Pulled the keys out and never had a problem.

Kicking up an older thread as I just returned from my Indy mechanic for similar issue. Tested all circuits and found my factory radio to be the cause-with radio connected it was drawing 0.9-1.0 amps. With radio disconnected 0.2-0.3 amps. I do listen to music in my car so not sure what to do for replacement as I have the Bose system which I hear runs in its own weird way. Any aftermarket newer head units with Bluetooth available as a direct replacement for Bose system?

My Bose was DOA when I bought my car so I replaced it with a JVC (KD-R820BT). Has Bluetooth integration, for music and phone hands free, but best part was it lets you listen to your streaming apps for Internet radio. My car had the MOST system so I threw out the factory amp and installed 2 aftermarket amps (Rockford Fosgate prime R250-1 and alpine MRP-F300). I believe the alpine is driving the dash and door speakers, and the Rockford is doing the rear channels and sub. Problem with the Bose equipment is they run odd value ohm ratings for their speakers so it's hard to use aftermarket subs. These two are low ohm and have had no issues the last 3 years. Hope that helps.

I found that one out the hard way too, left my key in and it drained the battery flat. My son was home and said the car was beeping and buzzing.

It may sound weird but a bad electrical ignition switch can cause the battery to drain. Check other threads on faulty ignition switch.

Larry