86 300E Headlight Washer pump won't switch off

This turned out to be the result of the brushes on the alternator being worn out. Fixed that ($18 at Napa) but then the battery turned out to be defunct too. Bought a battery from COSTCO for 56 dollars. Same rating as the proper one ($180) but needed to make a custom clamp from some angle iron to accommodate the slightly higher lip at the base. Works like a charm at 1/3 of the price. The rest of the battery is identical to the Interstate one I replaced down to the red plastic cover on the plus terminal. I bet it was made by the same people who make the Interstate battery. I can buy two more before I break even. :)