Originally Posted by eltatertoto
the compressor does, infact run with the key off. ive been sitting outside smoking and ill hear it kick on in my dads car, which has been parked since november. we have to keep a trickle charge on it. if you pop the bottom of the back seat and pull the relay for ELC and leave it overnight you might just have your answer.
I thought it did, thanks for confirming this, I've never really sat out there all night with it hooked up, but I am doing the same as you are for your dads car, I am keeping a battery maintainer trickle charging it, if not within a few days a brand new fully charged batter will go dead and not recharge.
I have not taken the time to test and see just what it is that is draining the battery, I always figured it was the compressor since I'd been hearing it run a little more often when the car was on than it used to, even a mechanic that looked at it a while back said he thought he heard it going off a little to often.
I am pretty sure this would come from leaky air struts, I am replacing mine soon and I'll see if that stops draining the battery.
I see somebody mention a bad diode in an alternator, I also heard that a rectifier bridge can go bad, basically it will let current start flowing in both directions, which means it can start to leak current out of the battery when the car is off.
They mention it having a new alternator, if the alternator was replaced trying to remedy the same problem by the previous owner, and it still has a parasitic draw, then I think the alternator would not be the culprit.
Hope they get it figured out, I am no expert on this matter as I am still trying to fix the same problem, of course I took the temp lazy fix, and put a battery maintainer on it, which is just a band-aid really, but it works.
Eventually I intend to take the time to pull each fuse while watching for a drop in draw, before I am
Here is my temp fix for the issue, it is better than having to replace the battery every few days if the drain is as bad as mine, it comes with everything you need to quickly connect and disconnect it, I leave it under my hood on the radiator hose when the car is cool, after I get back from a trip I leave the hood up a bit, and just sit it on the air-box area, then I let the hood down easily, not closing it all the way, the charger is so small it lets the hood still come most of the way down with it there.
So far it has worked great to keep me from worrying about chasing down the drain at the moment, of course I recommend finding the problem and fixing it, not bandaging it as I have.