Common places voltage can 'leak'...

[Storm-Chaser]

Is there any crud on the top of the battery? I had one instance where the crud on top of the battery was allowing minor current flow across the top of the battery, discharging it over time. If one of the battery posts or caps is venting gas, it will create a conductive coating on the top of the battery, which will accumulate dirt/dust and become that black crud you see on top.


Are all batteries the same - yes and no.

Have you had the battery load tested? If it is marginal, the combination of a continuous minor draw, short trips with the UDPs, and cold-soaking at night may be what's killing it.

I'd try what itwonder and SHOZ123 have posted. First night, disconnect the battery overnight and see if it starts - that will eliminate the battery as a direct cause. Second night, pull the ignition cylinder. Third night the power feed for the car alarm. Fourth night engine compartment fuses for the HOT in ACC power feeds. Fifth night fuses for HOT in RUN.


hawkeye18 also brings up something to consider - the Remote Keyless Entry Module (RKEM). Several have posted in the past a range of funny electrical things that happen when the module goes bad - and that's the same module that should time-out and shutoff interior courtesy lighting after 45 minutes . . . .

My understanding is that the underhood light is switched by an internal gravity switch inside the small light housing. The glove box light by a mechanical switch in the glove box latching mechanism, and the rear trunk light by the small mercury-switch on the left trunk hinge (that small black cylinder on the harness leading into the rear deck lid).


Oh, 1A = 1000mA. So 500mA = .5A !

We promise we won't tell your boss . . . .

 

[hawkeye18]

Well... I guess mine must be a special version, cos all my lights turn off after 45 minutes. Whether the doors are open or not. It gets quite annoying when trying to work on the car at night.

 

[93rev2sev]

Your battery may have an internal short or a renegade cell(a cell that all of a sudden decides that it's going to reverse polarity).

This usually happens when a battery is drained "deader than a doornail" and happens more often than people think...according to my electric car building/electrical engineer friend.

Try another battery.

 

[NJSHO]

Discharging a battery that many times can **** it unless you have a deep cycle. Also, using your alternator to recharge a dead battery can **** it in two ways:
1) Charging a deeply discharged battery with the alternator can cause the alternator to overheat and wear prematurely
2) the battery acts like a big capacitor smoothing out voltage spikes. If the battery is truly dead, ie. open condition, these spikes will act on the alternator. This was the reason the VAK system failed from my understanding. Pulling the alternator out of the charging loop caused the magnetic field to collapse, creating large voltage spikes.
I would invest in a automatic battery charger (about $40 Link) for times like this, plus it has built in alternator check.
I would start with the 10Amp range on the multimeter doing the current draw test. If you, open a door or the trunk in the milliamp range, you will blow the multimeter fuse. To take a current measurement the multimeter has to be in series (inline) with the load, not parallel to the load as with a voltage measurement. Not sure if this was gone over already but I figure Id throw it out.

 

[Storm-Chaser]

All of my 95's do this as well for the interior lighting. I've never seen if it affects the rear trunk light. My underhood light does not work because of whoever previously working on the SHO, hacked the damn harness.

Well... I guess mine must be a special version, cos all my lights turn off after 45 minutes. Whether the doors are open or not. It gets quite annoying when trying to work on the car at night.

 

[SHOZ123]

«1995 Taurus/Sable Table of Contents»
«Group 01: BODY»
«Section 01-14B: Door Lock Control System, Electronic»
«DESCRIPTION AND OPERATION»



Door Lock Control System, Electronic

The electronic door lock control system has four main components:

The electronic door lock control processor located under the package tray in the luggage compartment on sedan models.

The electronic door lock control processor is located behind the LH quarter trim panel on station wagon models.

The five-button keyless entry keypad on the driver front door.

The alarm and lock system antenna.

The four-button (hand-held) keyless entry remote transmitter.


The electronic door lock control processor performs the following functions:

Unlocking driver front door.

Unlocking all front doors.

Unlocking luggage compartment door.

Locking all front doors.

Automatic locking of all doors when all doors are closed, the ignition switch is in the RUN position, someone is seated in the driver's seat, and the transmission is shifted through the REVERSE position. This feature is available only on vehicles equipped with automatic transmissions.

Turning on interior lamps, keyless entry keypad and keyhole illumination after any button on the keyless entry keypad is pushed or either front door handle is lifted.

Turning on interior lamps and keyhole illumination when using the keyless entry remote transmitter.

Activating and deactivating PANIC security feature which sounds horn and flashes parking lamps.

Activating battery saver feature which removes power from convenience lamps and interior lamps 45 minutes after last input to electronic door lock control processor.

The electronic door lock control processor will also accept and store a temporary entry code. Either code will then operate the electronic door lock control processor.

 

[Eric VerValin]

I'm going to have to double check my 92 CD and see if that module is the same thing in mine. Only reason I say this is that I know the newer SHO's have some sort of alarm / keyless entry system already don't they? Mine is aftermarket, and I dont recall ever having a key fob for this car, or my 91.


And yes.. I did get the meter in the right spot, inbetween the cable end, and the empty battery terminal. And I did even do a few things to make sure it was working. I opened the passenger door, and seen the lights come on, then then trunk, and it acted like it should. But then went back to .05A, when it was on the 10 A setting. Yes I am aware that 500ma is .5A but when I read that the normal was 500ma, I assumed I read my meter wrong or something... ?


I tell ya tho, I do like that charger... I have a "manual" as opposed to an automatic charger.. and yes I know better than to charge a dead battery with the alternator, espically in the cold... I'll get this battery on a charger for a while and see what happens.

You guys are great! So much good info in this post already!

 

[Shoaz]

It does sound to me like your battery may be the culprit. Do you have another vehicle with which you can swap batteries for a bit?

And xN on the batteries aren't all alike issue. I've been slowly switching everything to Optima (well, I was until their prices went way up), since the end-of-life failure mode appears to be softer than it is for more traditional batteries. I'd like to not get stranded without warning when the battery decides it's done.

 

[SHO_DOODmorrris]

it might be your ignition cylinder, it is probably worn out and you are turning it back into accessory position. I have had a Taurus come into work with the similar problem kept killing battery, well the ignition cylinder was worn out and you could pull the key out while the key was in any position.

Just some food for thought. all my cars have new lock cylinders in them for that reason.

lols i dont even need my keys to start my car XD... i bet thats why it was drianing all the time last winter!

 

[Eric VerValin]

Ok.. well here it is... You can see, 770CCA @0 Deg.. 900 @ 32... manufactured 11/07 Johnson Controls.. here in Fort Wayne I believe.. same place who makes die hards and az advance whatever...

This first one was a test... and is the reading I got with the trunk open... (1 194 bulb)





This is when I closed the trunk..



So... .48 - .04 = .44amps x 12volts = 5.28 watts... sound right for a 194 bulb? sounds ok to me.. I'm not sure.. so there is your "is your meter ok" question. And still.. .04 amps.. shouldn't be killing this thing.


And it measured like 10 volts when I pulled it completely. I put it on the charger..a nd this is what I get...




Sounds / looks like a bad plate / cell in the battery maybe? Arent there 6 of them? 2v a peice more or less right?

 

[Eric VerValin]

Ok.. pulled it off the charger... says 12.70 volts... 12.69... 12.68... 12.67... Me thinks its a bad battery..

That was 5:35.. its now 5:48 and I'm at 12.57 volts.. Going to get it tested / replaced now... will let ya know what they say.

 

[NJSHO]

That amt. of voltage drop directly after being charged should be normal. If it kept going after half an hour Id say bad battery. If the battery is discharging itself, it should be warm.
Also, the auto charger I posted before will test for dead cells in the battery.

 

[Eric VerValin]

Well.. after waiting on a 15 minuite load test, the battery came back as bad, so I got another one. I think I'm going to get my alt rebuilt again, as I know that could possibly have an effect on things. It's the only thing not new under the hood electrically.


But after only 2 months in service? Somethings gotta be wrong with my alt I would think.. but last time I had it checked, it was ok, who knows...

 

[Devin]

Like I said, I had an alt installed for four months, but it was driven very few times between that and NAPA tested it and it failed. I replaced it and my Diehard is happy.

 

[Eric VerValin]

Well isnt 92 the year of the lower output alternators? Coupled with my UDPs can't help either. If I get it tested... what kind of amperage should I see @ say 1500-2000 rpm?

 

[Storm-Chaser]

If/when you get the alternator rebuilt, ask if they can rebuild it to produce higher amperage. It is possible to increase output on the 94-95 alternator from 130A to 200A - so I'm pretty sure the rebuilder should be able to increase output to at least 130A.

 

[Eric VerValin]

I'm goin right now.. my usual guy who rebuilds my stuff, dosent stock mitisubishi alternator parts anymore... so I have to go to the other shop in town... Kinda more known, but also a little more expensive.. I'll ask him and see what he says...

I'm assuming they are bigger brushes? I know I need a bearing in it, I'll see what else it needs, no harm in replacing everything tho right? Kinda the way I've been treating this car anyway.. doing a lot more than I need to probally..

 

[NJSHO]

To get more aperage, they would probably have to rewind the thing. I think there is a write up on here on how to use a gen 3 alt on a previous gen taurus. I know manyshos has done it.

 

[SHOZ123]

A G3 SHO alt mounts to the block 90 degrees from the pulley. Maybe some other Ford alt.

 

[NJSHO]

maybe its a gen 3 slo alt. its the ones that are always on ebay.