#Drain

Peter writes:

I drive a 2010 Toyota Prius. From top to bottom, I’m thoroughly impressed by the technology in this car. And yet this engineering marvel is so easily disabled by its inferior owner leaving a dome light on overnight and draining the 12V battery.

Is there any technical reason cars allow the 12V battery to be drained down beyond the point where the car will start? Who needs that extra 6 hours of dome lighting?

TTAC commentator claytori writes:

Hello Sajeev,

This email is about my 80-year-old mother-in-law Shirley, who is a sweetie and thinks I can fix anything. I hit the MIL jackpot.

Shirley owns a 2010 Lincoln MKZ 3.5 V6 with about 35,000 miles on it. About a year ago, the battery died on the Lincoln. CAA replaced it with another battery with a 13-month replacement warranty, on which less than 1 week remains.

Two weeks ago, the car wouldn’t start again, so I boosted it from my Saab 9-3, which sits beside the Lincoln in a heated garage. It started right away. As she doesn’t drive it more than about 3 miles at a time, I drove the car for a day to charge up the battery.

The battery was great for two days — then dead again.

TTAC commentator kericf writes:

Sajeev,

I know you experienced the deluge of rain in Houston (Last October, and it was pretty bad. —SM). We live on the north side of the city and own a six-month-old 2015 Ford Expedition EL that has been outside its whole life (it doesn’t fit in the garage). It has seen much heavier rain than we had this weekend, but not a storm that lasted so long.

Water somehow got into the headliner and dropped into the interior. It does have a sunroof and roof rack. The dealership has only had it a day but hasn’t been able to figure out the source of the leak. It hasn’t leaked before. We are baffled and I have a feeling the dealership will be too.

Longtime TTAC Commentator ajla writes:

Hi Sajeev,

I do a more through job at the time of purchase, but every year after I do a drain/refill on the radiator and replace some transmission fluid by using my fluid extractor to vacuum up as much ATF as possible through the dipstick tube.

I know that I’m not getting all the fluids exchanged this way, but my question is how much of a positive impact is this regiment actually having on my cars? Am I just wasting my time? I haven’t suffered a mechanical failure since I started doing this, but I don’t know if that proves much.

Keep in mind that the vehicles I tend to own are 20 to 30 years old.