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1996 Grand Marquis Battery Draining Overnight


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wonderloss
Novice

Jan 25, 2011, 7:18 AM

Post #1 of 18 (10920 views)
1996 Grand Marquis Battery Draining Overnight Sign In

1996 Mercury Grand Marquis. Battery dies overnight. Problem is intermittent. Thought it was a short in the starter, replaced the starter two weeks ago, and did not have any problems until yesterday. Car had sat for 2 days and did not have enough power to start. Battery at ~3 volts.

Looking for advice in trying to locate the source of the drain, especially in a car with many components that constantly draw power when the car is off.


Tom Greenleaf
Ultimate Carjunky / Moderator
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Jan 25, 2011, 7:54 AM

Post #2 of 18 (10911 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

That's a pretty fast drain. You really should charge battery with a charger and fully test it first. Battery alone after a few hard drains could be junk by itself.

With one this speed if battery known good you can put a test light with incandescent bulb (old trick) between disconnect neg battery post and battery. It should be off. If test light is on could be delay interior lights and not conclusive. Pull bulb out or disconnect hood light as the test won't work if it is supposed to light. Hard, but you can't open doors but pull fuses one at a time and bet one will make test light underhood go out. That just tells which circuit has the issue if a real drain to chase down from there.

Some foolish but real drains are reading lamps you don't notice are on, trunk light, glove box(s) that light, hood light.

I'm thinking that the battery will test bad under load not just a volt test when charged especially one that had gone down so many times and that's real hard on alternator if you are just jumping it and can kill it!

Happy hunting,

T



wonderloss
Novice

Jan 25, 2011, 8:14 AM

Post #3 of 18 (10910 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

The battery is new, and I had it tested after the last drain and it was fine. I have not tested it yet this time. I have a battery charger, so no jumping.

I tried pulling fuses before, both from the fuse box inside the car and under the hood. The test light never went off. I ended up pulling every fuse under the hood, and I put them back one by one, and the light came on with several of them. I do not have the list with me. With the starter circuit, it was a very dim light. The others it was bright. I think the light was coming on because those are circuits that have always-on components, such as the computer, the keyless entry, etc. Am I mistaken?


Tom Greenleaf
Ultimate Carjunky / Moderator
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Jan 25, 2011, 9:41 AM

Post #4 of 18 (10904 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

96 was the beginning of OBDII for all models that year and up. Computer is using milliamps and several for a while when just shut down. Milliamps won't light an incandescent bulb well but would an LED test light.

Did you replace the starter yourself? How did the connections look and I know those are a b*itch! Could starter be sending off juice as it's empowered by pos battery cable all the time? Should be the 4.6 engine and that gets corroded there easily especially in the snow/ice belts where salt is used on the roads.

There is a whole harness I believe sold for those that go bad but not usually a drain but it's a maybe on the list.

Things that stay empowered off the top of my head are interior lights, reading lamps, power ports and cig lighters - some of these could have them in rear door panels too, trunk light, any glove box lighting, horn, brake lights, headlights, parking or running lights and a trickle to save memory for any settings for clock and other things depending on what it has.

None of the listed things should draw that much or none or if really shorted would blow a fuse.

Running out of ideas but a test for the battery would be to disconnect it and charge it. See if it holds a day if you can afford the time. That wouldn't trigger the test mentioned though TMK.

Scratching head here? A mild short at the starter solenoid and or harness there is getting higher on my list of the may-bees. A dead short would smoke some wires which isn't the case. Can't think of much else if all fuses pulled can still cause a drain?

There should be about six square relays under a cover marked underhood and some of those items do have residual power waiting so those are on the list too. Common for failures on many of those but none lately. Usually the failure is the car cranks but doesn't run when those fail. Never saw one cause a drain but doesn't mean it couldn't somehow??

T



wonderloss
Novice

Jan 25, 2011, 9:58 AM

Post #5 of 18 (10900 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

Thanks for the advice.

I am not sure if the test light is LED or incandescent. I will have to check that. I am going to get a multimeter to measure current draw for my next stage of testing.

The connections on the starter were not corroded. I am in Central Florida, so no salt and snow, but a lot of rain.

Solenoid is attached to the starter, so both were replaced as a single unit. That does not rule out the possibility that the new one is also bad.

I pulled relays too, when I did my first set of testing.

I will not get to do any major testing until this Saturday, though I can charge the battery and see if it holds a charge.


(This post was edited by wonderloss on Jan 25, 2011, 9:58 AM)


Tom Greenleaf
Ultimate Carjunky / Moderator
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Jan 25, 2011, 10:41 AM

Post #6 of 18 (10895 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

Quote">>Solenoid is attached to the starter, so both were replaced as a single unit.<<"

The chances of two starters having the exact same problem of THIS sort is incredibly unlikey.

Other note: You said "intermittent" so it could be wiring at the starter with burned insulation that just barely can touch the wrong things. Intermittent problems are a nightmare for all of us.

I know it's tight there but get a mirror or whatever and see if you see anything funky with wire insulation as a clue?

TMK - the incandecent test lights the bulb inside is easily replaced - an LED wouldn't be,

T



Hammer Time
Ultimate Carjunky / Moderator
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Jan 25, 2011, 4:29 PM

Post #7 of 18 (10890 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

This discussion has happened here before and Tom knows my opinion on this.

My opinion is that you should not attempt to check this using a test light. All late model vehicles these days are loaded with modules that have timers and most trigger when the battery is disconnected so it is completely normal for most vehicles to have a degree of parasitic draw and will light a test light when in reality, there is no problem. You need to know exactly how much current is being drawn for a couple of reasons. This is why my opinion is that there is only one way to measure draw and that is with a digital ammeter and not a test light. Test lights were fine on older vehicles but will not tell you what you need to know on newer vehicles.

Here is the accepted procedure that will tell you what you need to know.

You will need a digital ammeter and a jumper wire with clips on the ends to do this.
First rig any door switches so you can have a door open without triggering the interior lights and unplug the hood light. Remove one battery cable and attach the meter in series between the battery cable and battery post. Take the jumper wire and also attach it the same way. Leave the jumper wire on for at least 10 minutes to expire all the automatic timers. Now remove the jumper wire and read the meter. Anything over 50ma is too much draw. The way you locate this is to start removing fuses one at a time until the meter drops to normal level. This will be the circuit with something staying on. Determine what components are part of that circuit and check them individually until the problem is isolated.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



wonderloss
Novice

Jan 30, 2011, 5:18 PM

Post #8 of 18 (10871 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

Saturday, I checked things with the multimeter. The current draw was 65 mA. This did not seem excessive, especially not enough to kill a battery. Today (Sunday) I tried to crank the car, but it would not crank. Battery showed 11.5 V. A couple hours later, I went to the car and the lights were dead. Voltage was less than 4 V. Any suggestions?


Hammer Time
Ultimate Carjunky / Moderator
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Jan 30, 2011, 6:39 PM

Post #9 of 18 (10866 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

65ma is a little high but it would take considerable time to bring a good battery down. You need to have that battery tested.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
Ultimate Carjunky / Moderator
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Jan 30, 2011, 6:47 PM

Post #10 of 18 (10863 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

I'm with HT on the testing by better than the old test light (regular at battery way) and by his specs you are over the limit. As to how fast that draw would take down a battery would be totally dependant on how strong the battery was and how long it was left draining.

Other note: If even a fairly decent or newer battery is taken down too many times it becomes part of the trouble as regular lead-acid batteries don't tolerate being drained too low too often. If very cold and drained they will quickly self destruct even if not the up front problem,

T



wonderloss
Novice

Jan 31, 2011, 9:14 AM

Post #11 of 18 (10856 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

Sorry. I was not entirely clear with my explanation.

I tested the car on Saturday, starting with a fully charged battery (12.6 V). Current was ~65 mA. The car was left alone overnight. I checked the battery voltage the next day, after ~20 hours. It was 11.5V. When I tried to start the car, it clicked but did not turn over. When I went back to the car a couple hours later, it was dead, and the battery only showed ~4 V. It seems something happened when I tried to start it that caused the current to drain very rapidly in a short amount of time.

My first thought is bad solenoid, but I just replaced the starter. Perhaps ignition switch? Something else in the starting circuit?


Hammer Time
Ultimate Carjunky / Moderator
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Jan 31, 2011, 9:15 AM

Post #12 of 18 (10851 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

I still say have the battery tested before doing anything else.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
Ultimate Carjunky / Moderator
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Feb 1, 2011, 6:05 PM

Post #13 of 18 (10832 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

Agree with HT - the $ is on that that battery is toast,

T



zmasterflex
User

Feb 10, 2011, 8:53 AM

Post #14 of 18 (10802 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

I know that im going to get flak for replying to an old post but this is too good to pass up. I've always wondered how to test a battery drain problem and this post explains it very clearly. The one thing I dont understand is the jumper wire.
"Take the jumper wire and also attach it the same way. Leave the jumper wire on for at least 10 minutes to expire all the automatic timers". How thick is this wire and how does attaching it for 10 mins help expire automatic timers? Thanks for the clarification


Hammer Time
Ultimate Carjunky / Moderator
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Feb 10, 2011, 10:29 AM

Post #15 of 18 (10797 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

The timers will restart every time the power is interrupted so it allows you to get everything into position and the wire will bypass the meter in case the timer flow exceeds the 10amp capacity of the meter which could also prevent the timers from expiring when they should.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



wonderloss
Novice

Feb 11, 2011, 8:22 AM

Post #16 of 18 (10791 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

It has been a while since I replied, but I wanted to give an update. The battery tested good at the parts store. I replaced the ignition switch, and things seemed fine for a couple of days, then it died again. I have not had a chance to do any more work since then. I am really at a loss of where to look.

It seems like the battery holds charge fine for the most part, then suddenly goes dead in a very short period of time. I am going back to thinking it might still be the starter, but I do not want to have to pay to get it removed and have it tested until I have ruled out other options.

Is there a way to test a starter for a short while still installed?


Hammer Time
Ultimate Carjunky / Moderator
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Feb 11, 2011, 8:38 AM

Post #17 of 18 (10789 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

The starter won't drain the battery when parked and removing it won't tell you anything either. I gave you the procedure to determine if there is a draw and how to find it.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
Ultimate Carjunky / Moderator
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Feb 13, 2011, 7:07 AM

Post #18 of 18 (10775 views)
Re: 1996 Grand Marquis Battery Draining Overnight Sign In

wonderloss: Car battery flakes as it ages and shorts a little or a lot but might still test good. The flakes touch the bottom of the plates OR if newer may have been mishandled before you got it and be intermittent. Regular car batteries hate state of discharge which shortens their life or kills them for good OR do intermittent funky things. Starting should only take up perhaps 5% of it's power which quickly get put back to full charge once running if all is right.

Wish you could test this with another battery and if problem never returns you would know it's playing games with you,


T







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