Since i am a newbie to this forum, i'd like to says hello to all user.
So anyways, i just bought a 1988 Ford 4-b(R)anger and having electrical problems. The problems seemed to discharge batteries overnight. Thinking that it maybe just an old battery, went to get a new battery installed. Drove the car, went home, tried starting the the next day and the battery is dead. So we decided to disconnect the battery at the end of the day. Next day worked with my dad on the problem and found this very interesting issue. Whenever the + battery terminal is disconnected, the wiper seems to have a life of it's own and run uncontrollable (non-responding to wiper controls) until you connected back the + terminal to the battery.
We recorded the battery voltage, then compared with the engine on, we expected additional voltage, we do (something like 2-4 more).
So to check if the alternator does work, we removed the + terminal off the battery (engine still running) saw wipers started uncontrollably.
I don't think its a good idea to ever remove the battery while the engine is running. I think the alternator regulator and battery work in a closed loop to control the voltage the alternator pumps into the battery. I assume that without the battery to regulate the alternator, the alternator's output voltage probably jumps up to some higher than normal level. The windshield wippers are controlled by a relay with a solid state time delay circuit. The higher than normal voltage is probably causing the time delay circuit to do some unusual things. This is all a guess, maybe some of the more experienced users can add some thoughts..........