Paging Click and Clack: car electrical problems

Factual Questions
1

I have an '86 3.0L V6 Mercury Sable. It may be relevant to this question that the car is seldom driven (once a month).

9 months ago, it began draining the battery while parked. I figured there was a short somewhere, but the car was otherwise sound. I installed a quick disconnect for the battery terminal (positive), and as long as I disconnected it when I parked, it was hunky-dory.

More recently, though, the car refused to start. It was also unjumpable. I removed the battery and took it to a battery place. The technician determined that there was no acid left in the cells. He told me that it was “fried” from a short or something. Anyway, I purchased a new battery, installed it, and the car promptly started.

Next, I brought the car back to the same battery place. With the car running, the technician read the voltage across the terminals. It was 17 volts. This dropped to 14 with the headlights and heater on.

“There’s yer problem,” he said, “the alternator’s overcharging 'er.”

Now for my questions:

  1. Is the alternator overcharging if the voltage across the battery is 17V?

  2. Can this be related to the current-draining short that cropped up 9 months ago?

  3. I’d like to get rid of this car. What is the simplest way of resolving these problems?

2

1)Yes
2)Possibly requires a test to find out where the draw (not short but rather a draw) is
3) Depends on how ethical you are. Fix it and sell it, or lie through your teeth sell it as is and hope that yo don’t get stuck on the karma train tracks with your new car.

3

What Rick said.

A little elaboration on #3:

The repair for the overcharging is to replace the alternator.

As for the battery going dead while sitting for a month, there may be a problem with the car, or it may have been a weak battery that couldn’t hold up to normal parisitic drain. If it was the battery, it’s already fixed. The thing to do is to test the vehicle for drain amperage ( = draw). If it’s within specs, you’re done. If there is excessive drain, the next step is to find and fix the cause of it.