Town Car battery drain

Town

Senior Member
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Ottawa Ontario Canada
The 1998 and up Town Cars have electronic systems that monitor any activity (unlocking or opening doors, opening hood, opening trunk, etc) that may signal the imminent operation of the car. These systems consume small amounts of power (all the time) of about 40 miliamps for 1997 and earlier models and up to 50 miliamps for 1998 thru 2002 models and up to 80 miliamps for 2003 and up models. A healthy battery will sustain this drain for weeks and still allow the vehicle to start. When the monitoring system detects an activity it immediately wakes all the systems (and the battery drain spikes big time) ready for a startup. If the startup does not come in about 40 to 60 minutes the systems go back to sleep and leave the monitor ready to react next time. However, a failed diode in the alternator or an electrical fault in the car's electrical system may cause a battery drain overnight or just a few days and prevent the car from starting.

Attached is a document that looks at what may be done to identify an electrical drain problem and search for the source. This approach may be used for other vehicles.
 

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heavyhaulerss

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The 1998 and up Town Cars have electronic systems that monitor any activity (unlocking or opening doors, opening hood, opening trunk, etc) that may signal the imminent operation of the car. These systems consume small amounts of power (all the time) of about 40 miliamps for 1997 and earlier models and up to 50 miliamps for 1998 thru 2002 models and up to 80 miliamps for 2003 and up models. A healthy battery will sustain this drain for weeks and still allow the vehicle to start. When the monitoring system detects an activity it immediately wakes all the systems (and the battery drain spikes big time) ready for a startup. If the startup does not come in about 40 to 60 minutes the systems go back to sleep and leave the monitor ready to react next time. However, a failed diode in the alternator or an electrical fault in the car's electrical system may cause a battery drain overnight or just a few days and prevent the car from starting.

Attached is a document that looks at what may be done to identify an electrical drain problem and search for the source. This approach may be used for other vehicles.
I have a 97 town car, would these tips & procedure apply ? I noted the 98 & up years.
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HowardS

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Hey Folks, im a German Guy who stay at Austin till next Summer and i bought a 1999 TownCar. And this (maybe) drains the Battery to... but not like described here in one or two weeks but in round about one Month. Could that be?? Or is there may another Problem?? Normally i drive every weekday only 6 Miles to my Work (3 miles one Way)... so its maybe only a small drain and i have it because i only drive not a long enough every day to charge that. I also was at a Mechanic and he said the Alternator is okay...

Any Ideas??
 

Town

Senior Member
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Ottawa Ontario Canada
Welcome.

A member here with a 2007 model went on holiday and left his battery connected and the car in normal working condition. When he returned in 32 days the battery was completely dead. Your car, if in perfect condition, will have a continuous battery drain of around 50 milliamps and that will spike above that level. So it will drain in time. Just how long depends on the state of the battery and how well charged when left to sit. Batteries don't like sitting uncharged, they sulfate and lose their ability to retain a charge.

So I think your system is working as one would expect, it is being drained regularly and not charged fully. So you need a battery charger to top up the battery regularly. A regular battery charger would have to be monitored to ensure it does not overcharge, even at the low charge rate. You can get battery chargers that monitor the battery charge and give it only as much as it needs, and some can be plugged into the cigarette lighter. This battery top up will eliminate the sulfate build up and therefore stop it from hardening and rendering your battery useless. Some of the more expensive ones will pulse the current and voltage to break up the sulfate deposit on the plates and restore battery power and reserve capacity.

Good luck, and enjoy your stay in the US.
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HowardS

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Thanks for that long Answer. If i've u right understand the Battery Drain is a normal thing at a TownCar?? in Otherwise if i drive more than the 6 Miles / Day it would charge the Battery and i did not have the Problem? I have a brand New Battery i change the Last one at Walmart because it was also only one Month old and i thought the Battery is damaged. But One Week ago i had the same Problem... the Battery was empty... but i could start The Car one time and i drove again to Walmart to change it :) i know its bad and not the Solution but it works for now because i want to have a Road Trip from Austin to New Orleans. Normally the Battery should work for that 2 weeks... hopefully!!! I also buy at Walmart a portable Power Jump Starter in the Hope if i had the same problem in the next 2 weeks i can help my self with that thing.

U said i need a "Battery charger"... but u mean a thing where i connect the Battery with a regular power supply system? But the Problem: i've no Garage ... that means i have to remove the battery from the car...bring it to my appt. and charge it there?? thats really not pretty handy.. :-(
can the other way be to find the "Drainer" or is it just regular the drain?

Howard
 

Town

Senior Member
4,399
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63
Ottawa Ontario Canada
Hi Howard,

You understand the problem. You cannot stop the drain except by disconnecting the neg terminal on the battery, and that means the PCM relearning the idle and trans shift schedule and you resetting the radio and EATC controls. Since you cannot conveniently charge the battery with a charger then just take the car for a longer drive occasionally. Your car's alternator will charge the battery quickly. Good luck.

Take care,
Art
 

bailsout

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Town, I'm new to the site: 2001 Connie. I don't see a forum for me but Town Car might serve. I use only my iPhone but am unable to open any of the attachments you often include. Thanks for all your inputs and advice.
 

Town

Senior Member
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Ottawa Ontario Canada
Welcome bailsout,

The tech articles for the Continental are in the Tech section, mixed in with the LS and other general articles. I have asked for the LS and Continental to have their own separate tech forums just like the Town Car and Zephyr/MKZ but it probably takes a while to do that.

I used to post attachments as Word files, but recognized that some do not have Word software so I usually post pdf formatted files which have a common reader called "Adobe Reader". It is available at no charge from the Adobe site. I have no experience with the iPhone but I would imagine there is a reader or an App that will allow you to access pdf files.

My son has an iPhone 5 so I will ask him how he accesses pdf files.

Good luck.
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Town

Senior Member
4,399
129
63
Ottawa Ontario Canada
Hi bailsout,

My son can read pdf files on his iPhone. He says to download adobe reader for free from the App Store. That should fix you up just fine.

Anything else you are having trouble with, related to this site of course?

Good luck.
 
Yesterday I drove the TC after 5 days of disuse. The steering was very heavy and the electrics didnt work properly. I diagnosed the steering as not enough air in the tires because a week ago the dealer did a periodic check and let the air out of my tires to just 32psi. I had them set at 40psi. I didnt notice the heavy steering when I brought it home, but I increased the pressure to 40 and this morning it was back to normal. But after the symptoms I had this morning, I am not sure the air was the problem.

After church this morning the car would not turn over so I had to have it jumped. On the way home I discovered that the interior light switch had been left in the full on position and that all the interior lights were on and had been on for at least 24 hours (I was working on the new GPS system yesterday). I think that was what drained the battery.

But now I am wondering if the battery being low could have somehow affected the tuning of the power steering??
 

Town

Senior Member
4,399
129
63
Ottawa Ontario Canada
Hi jimisbell,

No not 1.5 amps. The spike would be from 80 milliamps to 140 milliamps.

Good luck.
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Town

Senior Member
4,399
129
63
Ottawa Ontario Canada
Yesterday I drove the TC after 5 days of disuse. The steering was very heavy and the electrics didnt work properly. I diagnosed the steering as not enough air in the tires because a week ago the dealer did a periodic check and let the air out of my tires to just 32psi. I had them set at 40psi. I didnt notice the heavy steering when I brought it home, but I increased the pressure to 40 and this morning it was back to normal. But after the symptoms I had this morning, I am not sure the air was the problem.

After church this morning the car would not turn over so I had to have it jumped. On the way home I discovered that the interior light switch had been left in the full on position and that all the interior lights were on and had been on for at least 24 hours (I was working on the new GPS system yesterday). I think that was what drained the battery.

But now I am wondering if the battery being low could have somehow affected the tuning of the power steering??
Hi jimisbell,

The electronics are definitely affected by an unstable electrical system, just ask zinctwentyone about his battery and alternator issues affecting his air suspension and other components. From your other post I assume you have a continuous drain of 1.5 amp on the battery with everything off including the interior lights. I would have thought the battery saver feature would have switched off the interior lights after 20 mins or so but I never checked that. The lights would switch back on when you opened the door so you may have another drain. Any drain would be significant since you don't have much more than 60 amps available from a charged battery anyway before its flat (reserve capacity of stock Motorcraft 750 battery is 140 mins at 25 amp-hours load is about 57 amps and still just start the car.

Depending on your length of trip to church your alternator sounds a bit suspect as well but you can get it tested along with the battery. A failed diode in the alternator will discharge the battery quickly at a rate usually well above 1.5 amps.

My tire pressure is 32 psi all around (down from 32 front 35 rear since hearing that later models have 32 front and rear) and the steering has lots of power at parking speed.

Good luck.
 
Turns out its 2.5 amps. But I see no way to measure the quiescent number because to measure it you have to open the hood which will activate the standby mode. Its a Catch 22

From your comments it would seem to be that I have a real problem. I think that my installation of the new Audio, GPS may have a wiring error. It is wired with a "keep alive" function so that the presets are not lost when the key is turned off. But I must have made a mistake.

Off comes the dash trim again....LOL
 

Town

Senior Member
4,399
129
63
Ottawa Ontario Canada
Hi jimisbell,

Yes you can measure the value. The system lights up when you open the hood and connect your multi-meter between the neg battery cable and the neg battery post. But after a period of time the system goes to sleep and you have the 80 milleamps (that occasionally spikes to 140 milliamps) plus the 2.5 amp unwanted draw (2.58 amps spiking to 2.64 amps if there is no other draw). So at that point your access to the circuits should be clear so no opening of doors, etc. Just deal with the "audio" circuits to find your problem and correct it.

Good luck.
 
Well, it seems the audio system is NOT the problem. It is wired correctly.

When I pulled the dash trim I noticed that the parking light switch was ON. But I went on testing all the connections including if the drain dropped when I turned the Audio on and off and unplugged it.

What I found was that with the audio unplugged the quiescent drain is 450 milliamps (0.450 amps). With the audio connected in standby mode the drain goes to 600 milliamps (0.600 amps). Thats an increase of 150 milliamps. The Clock draws NOTHING measurable. The parking lights draw 1.5 amps.

That quiescent current is three times what you are suggesting, Town. But I dont have a problem with that because the battery can easily handle that for a week or more. Thats only a 7 watt load.

Apparently when I removed the dash trim to install the audio system earlier in the week I bumped the switch into the parking light position. BUT what I dont understand is how I would NOT have seen the lights when I went out last night and the night before to work on it. It was so dark I had to use a flashlight to find the car!!! But I could not see the parking lights were on ? ? ? I dont believe that.
 

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