Something electrical is draining my battery causing slow starts

Back in November I traded my sports car in for a more practical 2005 Mariner with 50K miles on it. I had noticed a somewhat delayed start during the test drive (at least compared to what I’m used to) and assumed it was the battery. Car drove great and I loved it otherwise so I made the purchase and went on my way. A couple weeks passed and I noticed the issue seemed to be getting worse and the engine took a couple more turns before firing up. I wasn’t surprised as most battery issues surface when the cold weather kicks in. I took it to the dealer and they found a leaky battery and replaced it and again I went on my way. Unfortunately the issue was not resolved with the new battery. I didn’t give it much thought thinking it was just the way the vehicle ran until the weather started getting progressively colder and my delayed start became even more prolonged. So back to the service department I go and wait patiently in the lobby with my book, hoping for good news. When they come back to me 2 hrs later they tell me that something is drawing too much power from my battery causing it to drain (alternator is fine) and they need to power everything down for a few hours and investigate the fuses in hopes of finding the culprit to the power drain. Later on I called for a progress check and they’re still stumped and would like to keep the vehicle overnight and see if they can figure out the issue after it sits for a night since (as I relayed) the slow starts are primarily in the morning after the car has sat. From what I gathered, the evidence of drain “disappeared” after a while during their little power down session.

Consequently, I have them investigating 2 other issues and I’m wondering if any of them may be related. One- I am having issues depressing the shift button to get the vehicle out of park (also more of a problem in the morning during the first start). Two- on occasion my key sticks in the lock cylinder when I shut off the engine and try to pull the key out. I spent some time online researching all of the above and it seems that there could be some issue with the ignition switch or a bad solenoid somewhere in the circuit… then again, maybe not? The only other bits of info I can offer since owning the vehicle are that I was having some issue with the rear hatch door. I kept getting the “door ajar” light after using the back hatch… but I’m pretty sure that was due to my own stupidity because the main door release and the top window release are right next to each other and I may have pressed the wrong one- slamming the back hatch hard took care of the light. The other thing is I followed the manual instructions and deactivated the seat belt alarms because I can’t stand the seat belt reminder beeping at me when I forget my seatbelt.

Update: I got a call this morning from the dealer’s service dept and they said my vehicle fired up fine this morning after sitting out all night. All they did was clean up some radio and fuse panel connections/wires (some of which had corrosion present) and the battery showed no signs of drain this morning. Is that really enough to cause battery drain? When I asked if the shifter button gave any resistance this morning they said that was fine as well, which makes sense if the connection from the brakes to the shifter release is electrical and the battery finally has enough juice for that to fire correctly. They suggested I drive it around for a few days and see if the problem comes back and in the meantime they’ll keep the work order open. I sure hope that simple fix took care of the issue because the last thing i need right now is to be stranded somewhere :confused:

Sounds like the dealer may have taken care of it. Keep an eye on it though, I’ve had a couple of cars that had phantom drains, chasing those is the least fun thing to do ever.

Yep drains are a pain in the butt to find…But before you go looking for a drain make sure you check amperage at the battery to make sure there is even an excessive drain occuring. You will need a amp meter or multimeter for that. And if you dont know how to do it here is how. First step turn off car keys out of the ignition, all windows rolled up, all doors shut, absolutely nothing can be on. disconnect the negative battery cable and let it sit for a few minutes without the DVOM hooked up. Car needs a few minutes to shut all systems down and if you hook uo the DVOM to fast it will most likely pop the fuse in your meter. Anyways so let it sit for awhile with the negative battery cable disconnected. then hook it up and switch the meter to read miili amps…I think 4 milli amps is the usual toloerance. Anything more then that and you have a drain somewhere in the vehicle…which means you have to start pulling fuses until you find out whats causing the drain.

Thanks for the suggestions. The mechanics at the dealer did test for drainage the morning I brought it in and found a drain of… 2 amps (I think)? I’m not very familiar with amps and mili amps but he said that was high and would definitely cause drain over a night or 2 with the vehicle sitting. Their suggestions was to power everything down so they could hunt for the drain source by checking the fuse panel. Evidently, by then, the drain stopped (weird). So I left it there overnight so it could sit for a good amount of time and they could try again with a cold start in the morning. At that point all they had done was as I mentioned above- cleaning wires and the bit of corrosion they found. Yesterday morning when they fired it up, they detected no drain. I have my car back now and it started it up this morning- still sounded slightly sluggish to me, but it was 30 degrees this morning also. In addition, now my radio doesn’t work. Clock works but I can’t tune in any stations. I remember them saying one of the things they were cleaning up was the radio and that might have been where the corrosion was, so I have to take it back at any rate to at least get my radio back. Hopefully the draining issue is resolved, but for me, things are never that easy haha.

Maybe the radio was the drain and now that the radio doesn’t work the drain is fixed!

A milliamp is just one thousanth of a amp. A typical battery current drain is around 15 to 25 milliamps that is used to keep memories alive in devices. That is a low enough drain to keep enough charge on the battery to be able to start the engine after weeks of sitting. Two amps of current drain is hugh and will be enough to drain the battery overnight. Hopefully the trouble will stay away but if it doesn’t the trouble should be pretty easy to pin down if it doesn’t go away by itself intermittently.

The radio trouble may be due to a disconnected antenna connection to the radio.

Sounds like you are due for further haunting…I don’t think its fixed…if the radio is now inop…and the issue seems to have abated…then that may have been it… The other issue was the door ajar…I believe there should be a light in the cabin associated with that…

IF you have PREMIUM sound…and the radio was having an on off issue…Don’t forget about the AMP in the rear of the vehicle…(premium sound again) If that Amp remained powered up because of a Radio fault, then there’s the issue…

Until your vehicle is as “complete” as you would normally like to have it…with all accessories in place and working…the issue remains to be seen methinks… I’d rather have everything working and not draining…and I think this was the entire purpose of trying to fix the vehicle…No?