Taurus alternator putting out 17.5 volts
That is too much, to state the obvious. From: http://www.fordification.com/tech/charging.htm ....- A problem that is not as easy to diagnose is overcharging, which occurs when the voltage regulator fails to limit alternator output. This causes the alternator to overcharge the battery, which in turn can ruin the components that use electricity. Also the sulfuric acid battery fluid vaporizes at a faster rate when too much current is being supplied. If the battery cells are allowed to empty, the dry plates will deteriorate and the battery will die. It is even possible for an overcharged battery to explode. (Should be about 12.5V +/- 0.3) with engine not running and with engine running 13.7V to 14.2V
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