have 2 99 crown vics, and 1 99 grand marquis.
all 3 of them the battery will die if left sitting unused for more than 5 days, and on my P71, it has a mind of it's own. i can drive 500 miles, shut the car off and it will not restart. but then i jump start it, idle it for 2 minutes, and it is like a new battery was put in. it may work fine for weeks, or die again the next day. and this is with new batteries in all 3 cars, and a new spare i swap into them when one dies.
Take them too a dealership and have the charging system analyzed, WBMS.
Then you need to go to a dealership that has techs that know what they are doing and the proper equipment to do the job properly
have an '06 Stang bought new as a toy (1800 miles in 3 1/2 years).......they all have a basic anti-theft system and I ordered the optional alarm system with motion & tilt sensors, etc.
if I leave it in my garage with the systems turned on, the battery is flat in less than a week......with the systems left off, it will last
2-3 weeks.same story: dealer says that's normal.
so I installed a trickle-charger....a Battery Tender Jr which I guess puts out about an amp. I plug it in if the car hasn't been driven in 3 or 4 days.....and it takes 2 days to charge-up.
pisser is: when the battery is completely discharged, not only do you lose the time & radio sets, but the transmission loses is memory (relearns after you drive it a while) and you have to manually reprogram the power windows to drop when you open the doors.
wonder what people = like New Yorkers = do where it's normal to leave your car in a parking garage for long periods.
Ask any collector and they will tell you follow the 30 30 rule. Run you car for a least 30 miles every thirty days and you should not have any problems. I have several collector cars, my oldest is a 1941 Continental convertible and my newest is a 1983 Continental Mark VI Signature Series Sedan. I can start and run all of my collector cars without any problems.
Mike......agreed: my collectors cars can sit for months and still start.......high power draw while sitting seems to be a phenomen of cars of the last few years.
have found that the batteries last years longer when they are matained with a full charge than when allowed to deep cycle.
and.....I'm jealous that you can run yours once-a-month: my 'Stang has been waiting with top down for a nice day.....but it hasn't stopped raining here (Ohio) for over 3 weeks.......and at this time last year was going to take it in for a pre-winter oil change: weather was finally nice enough in late May!!! must be the global warming.
Must be the additional sensors pulling extra power. My '07 GT has no problem sitting for a few weeks, but it gets plugged for the winter. Keep it plugged in, constant discharge to dead will wipe out the battery fast. Battery in my Harley just turned 9yrs old, still cranking fine, on the tender whenever it's in the garage. It has a OEM security system.
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