we were testing for a battery draining short and i installed a quick battery disconnector, and it worked. i decided to try and throw the switch while the truck was idling and it began to shake and shutter so i immediately figured the alternator took a dump and could even be our short we were looking for..so we get a new alternator and put it in and i tried to disconnect the switch again and it did it again..started running crappy. i told the guy to hold it at a high rev and i again disconnected the quick switch for the battery.well that screwed it up bad. now it wont run without constantly fluttering the gas and it dumps black smoke...the truck has 80k and runs great always maintained 5.8L with auto trans 89 econoline with a 12ft box...i think i disconnected the voltage regulator and blew the next module or sensor when i disconnected the battery that last time. im an idiot anyone ever do this before...please help

 

You don't disconnect the battery on any vechile that has a computer controling the engine if you do you can burn up more than a sensor or two. Good luck on repairing the damage that has been done.

 

Sounds like you blew the computer.

 

You could do that 'back in the day' when cars had generators. With modern cars/trucks it can cause damage.

Link:
http://www.forparts.com/techbattery.htm

Quote:
DO NOT DISCONNECT THE BATTERY WHILE THE ENGINE IS RUNNING!

On older vehicles with mechanical voltage regulators, it was a common practice to "pull" a battery cable while the engine was running. If the alternator was charging, the engine would keep running. If the alternator was not charging, the engine would stall. While this practice was not recommended, it didn't seem to do too much damage.

Such is not the case with electronic voltage regulators! Everyone knows what a voltage "surge" or "spike" will do to a computer. The modern automotive electronic voltage regulator has some of the same components as a computer. Pulling a battery cable while the engine is running will send a voltage "spike" throughout the electrical system of the automobile. This can, and usually does, damage the voltage regulator as well as other components such as the engine management electronics, ABS control unit, and electronic dashboard display. In fact, many new automobiles have specific instructions regarding the grounding of your body to the chassis of the car to prevent static electricity when working on delicate electronics. If they are this sensitive to static electricity, just think what could happen if a battery cable was disconnected!



If you're very lucky, maybe another alternator will solve the problem?
Good luck.

 

Welcome to FTE. There are better ways to test for a drain. With the newer vehicles you can fry a computer or module without trying hard at all. Pull the alternator and take it to get tested. I don't know what test equipment you have, so you might have to take it to a shop if the alternator is good, to find out what other damage there is. Good luck with it.