Need Electronics Expert

I have a 2012 Lincoln MKZ that when parked in the garage will have a dead battery overnight. I took it to a high volume Ford / Lincoln dealer with a high quality shop. They checked everything and found nothing. I have a Chamberlain / Liftmaster garage door opener that is about 25 years old. I always drive the car in and lower the door with the remote. I checked the specifications of the remote and it operates at 315 megahertz. I wonder if in lowering the door by the remote may trigger some sensor and turn on something to drain the battery. I have no way or knowing the frequency of the various sensors. I called the manufacturer of the opener and the engineer (?) only told me that they maintain no support for older units. I guess he does this to protect the company from litigation over other electronic devices. I am trying another experiment of driving the car in and lowering the door with the wall switch rather than the remote. I may change to a newer opener with a different frequency but first may call that Engineer (?) again. Any electronics experts around?

No, your garage door remote should not affect anything in the car. Even if there is a sensor in the car that can pick up the frequency of the remote (unlikely), it won't respond to the code your remote transmits. Being an older opener, it probably doesn't use rolling code technology, but certainly anything in your Lincoln would be rolling code.

I'd start with the basics: disconnect the battery when you park your car, then reconnect it in the morning. If the battery isn't dead, you know your problem is in your car and not in your battery. Then I'd just start pulling fuses.

The old method of putting a voltmeter in series with the battery won't work on most newer cars because the idle current draw is so high; there's a lot of electronics that need to be kept alive when the engine is off. But you can still put an ammeter in series with the battery (being careful to shut everything off first) and measure the current draw. If a good battery is going flat overnight, that's a draw of several amps which should be easy enough to detect.

One way to eliminate the garage door issue would be to park it outside the garage for a night or two and see if the battery still discharges. That would eliminate that potential problem.

More likely causes would be some of the "battery killers" that these modern cars are loaded with. Like headlights that stay on for a few minutes after you park the car. Proximity sensors that sense your approach with a coded key fob and turns on lights as well as other things. Are you sure that those things are turning off when they should?? Are things turning on (or trying to) when they should not? For that matter, what shape is your battery in??? Could it be that one of those convenience "features" is more than the battery can handle???

Bear in mind that there is no voodoo or black magic involved here. Most likely, your battery is weak. Other possibilities are that one of the modules that controls one of those "convenience" functions is not turning things off when it should. Like a heated seat, headlight timer, courtesy light timer, or some other doodad that is drawing current. One thing is sure: unless it is a weak battery, it takes a very substantial drain to draw down a battery overnight.

I am NOT an electronics expert, but have experienced the same scenario with my Chevy pickup- the glove box hinge had broken and allowed the lid to close, but not press the switch for the glove box light open. By walking into the dark barn, I saw the light around the edges of the glove box lid. Fixed the hinge, fixed the draw. JM2C. Good luck.

My parents had a new Honda, less than 3000 miles that had an occasional dead battery while parked in the garage for a few days. In the end dealer traced it to stuck AC relay that would hang up occasionally. Dealer found it on 3rd try.

Don't think the garage has any thing to do with it. We have a F450 at work that will drain the battery overnight. Everything is off and some times it drains over night. Some times it can sit for a week and start just fine.

I have a friend who has a 2014 Ford F150 (loaded) that was doing that about once a week, sometimes more sometimes less. Several trips to the dealer, and finally a demand that the lemon law would be invoked if it happened one more time.

Turned out it was a faulty switch on the shift lever in the console. With the ignition off and the lever in park the vehicle should have been off, but the ignition was staying on....sometimes.

The dealer was about to give up when one of the mechanics there found it by accident. Parts were replaced and it hasn't done it in a year now.

I would wonder if there would be similar parts on the Lincoln, as this pickup has a console with the shifter there instead of on the steering column.

(quoted from post at 06:09:33 10/31/15) I have a 2012 Lincoln MKZ that when parked in the garage will have a dead battery overnight. I took it to a high volume Ford / Lincoln dealer with a high quality shop. They checked everything and found nothing. I have a Chamberlain / Liftmaster garage door opener that is about 25 years old. I always drive the car in and lower the door with the remote. I checked the specifications of the remote and it operates at 315 megahertz. I wonder if in lowering the door by the remote may trigger some sensor and turn on something to drain the battery. I have no way or knowing the frequency of the various sensors. I called the manufacturer of the opener and the engineer (?) only told me that they maintain no support for older units. I guess he does this to protect the company from litigation over other electronic devices. I am trying another experiment of driving the car in and lowering the door with the wall switch rather than the remote. I may change to a newer opener with a different frequency but first may call that Engineer (?) again. Any electronics experts around?

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No matter how fancy the machine, it still has to follow the laws of physics. Measure for current draw from the battery when the vehicle is shut off. Has the battery been removed and load tested ?

Buddy of mine had a brand new Lincoln Navigator with less than 300 miles. It would start fine when cold, but try to restart it after it was warmed up and it wouldn't even fire.

It drove several Lincoln dealers nuts. It wasn't until he got Lincoln's Regional Manager involved that someone got serious enough to find it. Turned out to be some remote temp sensor that no one even realized was there.

If the fuse panel is easy to access, you might try pulling fuses one at a time overnight to see if it stops doing it when a particular fuse is pulled.

Had a newly rebuilt alternator installed on my Bronco II a few years back. Would drain the battery when sitting at wife's place of work. What happened was that the voltage regulator although new, was defective. When wife would park car, go around to passenger side, open door to get her stuff out, the dome light would come on triggering the voltage regulator to switch on due to system (battery) voltage drop. Regulator would then allow field in alternator to be energized, even though the engine was off. This discharged battery over the day's shift, and no go at the end of her shift. Took some real detective work to figure that one out. Then, we replaced regulator with new out of stock, couple times, with new. And they were defective as well! Finally dug old one out of scrap box - put it back in, worked fine as long as we had the car.

I'm no expert either, but I absolutely hate the "convenience" features I don't want or need: headlights that stay on, dome lights that stay on, radio that stays on all after you kill the engine. I won't buy a GM car because you can't start it with the headlights off. Sure a top notch battery will handle the load, but at some time it's going to bite you, battery low and uncontrollable headlights drain the battery on your only chance to crank it.

had a similar problem plus the battery would die while driving also. Dealer was stumped after several dealer service calls. An older mechanic at the dealer ship happened to walk by and I asked him what he would do. He turned to the service manager and said - give the guy a new battery. Battery was replaced and haven't had a problem for years. We sometimes miss the obvious.

I work on lots of these types of issues. First, I tell everyone they need to leave it with me for a few days. I put the rig on a flat stall and hood up an inductive low amp current draw meter on the positive cable and check it once in a while. Sometimes I will test drive the rig and then leave it some more. Internally shorted batteries that slowly go dead are very common. Bad door switches are also something to watch for. Vanity lights in sun visors are another one. Once in a while I will see a control module that won't go to sleep. Intermittent issues can be very difficult to solve.

My nephew has a F-350 diesel that would drain the batteries overnight. I disconnected one battery and jump started the truck and it ran fine. I went to charge the other battery and it pegged the 10 amp charger and triggered the charger relay big time. I took it to the house and used his charger--same thing. Found out he somehow reverse charged the battery. It had also blown the alternator.

The reason he originally recharged the battery was excess current draw with the ignition off.
I took off the starter cable and measured the current draw across the electronics, auxilliary cable with a digital meter. It showed a current draw of about 3-5 amps that my 30 amp analog current meter (borrowed from tractor supplies) did not show. So I then removed each fuse and measured the current draw across each fuse socket and localized it to one minifuse and left it for him to finish tracing it to whatever relay, device was defective. I forget which one.

My elderly aunt had a fairly new car (couple of years old I think) one time that was doing that. They finally figured out she had stuck a receipt under the lighted mirror on the visor. The flap was down/closed but that receipt was holding it open just enough to keep that light bulb on underneath it. It would drain the battery in a day or two.

Google " transport recalls usa or canada" and follow the instructions to type in your year and make , every bullitin and recall will be listed. My buddy told me about it the other day , so I looked up my old 94 chev 4x4 and it had a recall on the brakes .

Larry --ont.

Had Mercury Marquis that drained down. Finally, put in new battery. Same. One night my daughter, sitting in the back seat, saw light around the edges of the glove box door. Problem solved.

I was told to open the hood / trunk /glove box / console and imediatly touch the light bulb. If it is already too hot to hold, it was on long before you opened the device. Good advice to find an always on light that kills batteries.

Never put a voltmeter in series, only parallel. Ammeters go in series.