2008 CX-9 Touring Battery Drain

[joswald21]

Hello...if the car is parked for 3-4 days, when I try to start it the battery is dead. Something is draining my battery - actually, 3 batteries now.

Is this happening to anyone else?

 

[Carfo]

Hello...if the car is parked for 3-4 days, when I try to start it the battery is dead. Something is draining my battery - actually, 3 batteries now.

Is this happening to anyone else?

Do you have anything plugged into a 12v slot? Not sure about the 2008 model but some vehicles usually have an always on12v port and if something is plugged in there it could be draining the battery

 

[table5511]

Nope, have never had this problem on my 08. Let us know if you figure it out, that is strange.

 

[joswald21]

Do you have anything plugged into a 12v slot? Not sure about the 2008 model but some vehicles usually have an always on12v port and if something is plugged in there it could be draining the battery

Negative. Mechanic kept the car for a couple days. Couldn't find the cause of the parasitic drain.

 

[joswald21]

I got a tip that the ground connection shown in the pic could have something to do with a parasitic drain. Does anyone know what it's connected to?

 

[table5511]

You have a lot of corrosion. Maybe try replacing that bolt.

 

[joswald21]

Car has been at https://www.keystoneautoelectrical.com/ since 1st thing Wed (25th) morning. Still working to find root cause. Tech is confident the issue is caused by something in the cabin. He can duplicate the draw - no battery connected -> battery connected -> no draw happening -> ignition switched ON -> ignition switched OFF -> draw happening. Not a simple problem. We'll see...

 

[joswald21]

OK...here's the deal...Jerry at https://www.keystoneautoelectrical.com/ isolated and repaired the problem. The relay for the Rear Defroster was bad. Hard to believe, but that was the problem.

 

[Bren4Life]

I am having issue with my 2008 CX9 GT draining battery too.... Happened last week when parked for 2 days but got jump started immediately. Had battery tested and it is all good. Today after being parked for 2 days, tried to jump start and just clicks - lights flicker, etc but never would turn over.

 

[PTguy]

To DIY...you'll need a DC ammeter to measure the current draw. A clamp-on DC ammeter starts at about $25. Clamp around the negative battery cable and see what the current flow is. As jos wrote, it may take something like turning the ignition on then off, or whatever makes it happen on your car. When you see the current draw start pulling fuses. One by one pull then replace the fuse. Does the ammeter reading change? If necessary, take out all the fuses--make good notes of which value fuse goes into which slot; it's already marked, so pay attention. If you have all the fuses out and you still see a draw---it's time for a pro. The rear window defrost heater has a fuse, and this would have found the problem there but not the cause.

 

[rotorbaru]

OK...here's the deal...Jerry at https://www.keystoneautoelectrical.com/ isolated and repaired the problem. The relay for the Rear Defroster was bad. Hard to believe, but that was the problem.

Can you tell me where the rear defrost relay is located, I have a similar problem with my 2008 M5 GT?