vetsac

Hi all,

I have a puzzling battery/alarm system problem I hope someone can shed some light on. I've searched the forums here but haven't found anyone else post about this problem yet...

I have a 2006 Mustang V6 (approx 48,000 miles on it). I purchased it new.

I was out of town for a week, and came home to discover that my Mustang would not start (it was parked in its garage the entire time I was away). Prior to leaving town, the vehicle was running fine -- I did not experience any anomalies. After opening the hood, I noticed a lot of battery acid corrosion on the factory (original) battery POS and NEG terminals/clamps. Apparently the battery failed while I was out of town. A multimeter test confirmed that the battery was dead.

So I removed the dead battery (disconnected first the NEG then the POS clamps) and, using baking soda/water, cleaned off all the POS and NEG clamps and any other corrosion found on and near the battery tray area. I did not find any corrosion on any nearby wiring harnesses.

I then went to AutoZone and bought a new battery (a "Duralast 40R-DL battery" -- 590 Cold Cranking Amps, the same CCA rating as the original factory battery). After mounting the new battery and making its connections (first POS clamp then NEG clamp), I found that as soon as I touched the NEG clamp to the new battery's NEG post, the horn would sound constantly until I broke the NEG connection (it was a a constant "beeeeeeeeeeeeeep" as opposed to a "beep beep beep").

I talked to a service tech at my Ford dealer who said this is not normal behavior, and that I should try pressing the UNLOCK key on my fob to reset the alarm system after making that NEG battery connection. I tried that, and it did nothing. The horn still blares when the NEG connection is made.

Next, I tried removing the horn's relay in the fuse box so I could at least finish the battery connection and try starting the vehicle. I verified that I have good power to all devices (dome/headlights, power locks/windows, keyfob opens trunk, etc.). When turning the key to POSITION 3, I see all dashboard lights as normal, and I hear the fuel pump kick on briefly as normal. I then tried starting, but I get nothing -- no "click" from the starter or anything.

I called the dealer back, and talked to a different tech. He said this behavior is "definitely caused by the alarm system" because the battery was disconnected. He suggested I should push and hold the little "alarm system override" button underneath my dash while starting the vehicle. I did that, and still cannot start the vehicle. I tried doing this with the horn relay UNPLUGGED as well as PLUGGED IN -- but I still get the same behavior either way: unable to start the vehicle.

The tech theorized that perhaps the alarm module is not being reset for some reason, and that an "alarm guy" at the dealer will have to look at it. He said there's nothing I can do easily to reset the alarm module (i.e. pulling the alarm system's fuse, then reconnecting it, which -- on older vehicles -- will reset the alarm system, according to him).

So, before I end up having to have my Mustang towed into the dealer so their "alarm guy" can look at this issue, I'm wondering if anyone else has experienced this problem and has a solution?

I am assuming here the problem is with the alarm system -- caused when the original battery was disconnected -- because the alarm system is not being reset, it has activated its "STARTER DISABLE" feature.

I have both the "SecuriLock Passive Anti-Theft System" AND the "Active Anti-theft System" -- both installed by my Ford dealer when I bought my Mustang. When I turn the ignition key to POSITION 3 and see all my dashboard lights come on, the PASSIVE "theft indicator" light comes on for 3 seconds, then goes out (its normal behavior). It does NOT "flash rapidly or stay on for an extended period of time" as the manual says, which would indicate the system needs to be serviced by the dealer.

I have also tried the sequence to put the alarm system in VALET MODE, but I am still unable to start the vehicle. NOTE that the "Status Indicator" of the Active Anti-Theft system currently DOES NOT flash at all (normally it should flash about 1x/second for a Fully Armed system, or in a 'double-flash' pattern when in Valet Mode). Thus, an LED that is not flashing at all tells me that my Security System is DISARMED. Yet I still cannot start the car.

Does anybody have any idea how to reset the alarm system after replacing a battery? Or if the alarm system is not at fault here, what else could be causing this issue?

It seems ridiculous that I would have to go thru this mess (i.e. starter problems and having to go to the dealer) every time a simple battery needs to be replaced!

Thank you for anyone who has suggestions I can try or who knows what's causing this issue!

-Dan

Obsequious1

I used to have a 94 explorer with a alarm system. It would act up every so often and I'd have to hold the rest button under the dash to start it. Some times the alarm system would turn on my running lights and drain my battery, leaving my stuck. I did away with the alarm system but since it was wired into my remote door locks, I had to unlock it the old fashion way. It seems to me that you should've been able to start your car while holding the reset button in..

vetsac

RESOLUTION:

I'll post this here in case anyone else ever runs into the same problem:

I tried numerous things, even calling 1-800-FORD-KEY and talked to 3 different techs (all of whom gave me three different sequences to try in resetting the alarm system, none of which worked, and one of whom told me that the directions the PREVIOUS tech told me were for the wrong system!).

So I ultimately had to have my Mustang towed into the dealer. The dealer called me back the next day with the verdict: a card that holds the programmable memory of the alarm module (which plugs into the back of the bigger alarm module box) failed, causing the starter circuit to not go thru this card and into the module, resulting in a stuck open circuit that prevented the starter from working.

I asked him what may have caused the card to fail: he and the mech didn't know, but he theorized that perhaps maybe it suffered a surge when the battery was finally reconnected. The dealer also added that I should NOT have to do anything specific (i.e. a special sequence) to reset the alarm system the next time I have to replace a battery. These new alarm modules don't require any reset, according to him.

They replaced this card, tested other related systems, and found no issues.

So, the price of this repair? The breakdown:

New card for alarm module: $46.21
Labor to debug and install: $246.75
Towing fee: $179.63
Tax: $3.72

Total: $476.31

My extended warranty that I purchased on my Mustang paid for all of that, except $129.63 (a portion of the tow fee).

Hope this summary helps someone else!
-Dan

Timspony

^^^ OUCH!

Devil Wolf

good to know, thanks for the heads up.

aode08

never cared about a factory installed alarm.

You'll be somewhere and get stranded, not everyone has $500 laying around and time.

Get something installed that can be disabled or bypassed by hand or nothing at all,Chryslers lose the code when the batt is disconnected, to the door modules, the ignition and key fobs.


$ $ $ $

vetsac

Well this alarm module DOES have an override button, but because the card in the alarm module failed and caused an open circuit to the starter, the override didn't work anyway.

When you say "bypassed by hand", what do you mean -- actually connecting two wires together?