Ford Taurus' Flat Battery
courtesy of Bob, The Auto Answer Man
I have a problem with an intermittent flat battery on a 1995 Ford Taurus. Here are some numbers. Measurements were made with a DVM.
Battery Voltage (normal charging, engine running) 14 to 14.5 Volts
Battery Voltage (engine off) 12.7 to 13.2 Volts
Typical current drain (engine off) 7 mA
The 7 mA is probably maintenance current for the various computers (ECMs). It's also not nearly enough current to drain the battery overnight. Yet, this is a recurring problem. If the problem were a "hard short" or a solid "resistive short," I could troubleshoot this with a current meter, by pulling fuses and watching when the current stopped flowing, but that won't work in this case. I have removed all the interior lamps (65 mA each), and the problem is continuing. I am beginning to suspect one of the ECMs is behaving badly, perhaps turning lights on when no one is near the car. Since there's more than one ECM, it would be nice to know which one has gone bad. There's no point in replacing the ones that are okay. Any ideas how to troubleshoot this one? It's a new battery, so that's not likely to be the problem.
Hmm, it may be more simple. It simply could be a bad cell that is shorting or not holding a charge. Did you run a SG test on each cell (specific gravity)? This will tell you if a particular cell is having a problem. There may be some build up of sulfur on the plates). Be careful, though, when checking as it is acid and can cause harm if misused.
Bob, The Auto Answer Man
Have a car care question? Visit our automotive center and see if we've already answered it or a similar question.
Also in Home
- Ways to reuse an entertainment center
- The cost of using your clothes dryer
- Hay bale gardens
- Priortizing home repair projects
- Great ideas for decorating your entry on a dime
- Easy, inexpensive ways to grow from seed
- 10 ways to save money on your utility bill
- 5 simple and affordable luxuries for your home
- 5 frugal ways to expand your living space
- Top 10 DIY mistakes made by home 'handymen'
- 6 ways to save on home heating
- 7 ghastly critters that will eat your house
- Find the best mortgage rates in your area
- 3 ways to use a mortgage calculator
- Mortgage calculator: Calculate your payment and more
- Home equity calculator: HELOC vs. line of credit
- Mortgage refinance break-even calculator
- How much money can I borrow for a mortgage?
- Who offers the most home insurance discounts?