The alternator on my 1997 f150 is sparking. The sparking is not in the alternator but it is on the front where a cable is attached to it
have the same problem?
Wednesday, April 6th, 2011 AT 3:57 AM
Battery wire to the alternator is shorting to ground-disconnect the negative cable and fix it
Wednesday, April 6th, 2011 AT 4:00 AM
If you have a plug on the side with two fat black / orange wires, that plug is never supposed to be unplugged because it will degrade the connections. The very high current going through them will overheat them and cause them to burn up and arc.
Quite the design to use a plug that can't be unplugged. When you replace that design generator, the new one will come with a new plug already installed and you are instructed to cut and splice the wires. I wonder how many car fires have been caused by that design.
This doesn't apply if you have a single output wire bolted to the back of the generator case. I'm not sure how many years Ford used that poor design but they have caused a lot of fires. When arcing occurs at the bolt-on type of output wire, you can suspect there is already a shorted diode inside. That will cause the generator to overheat along with the output wire and connection. The heating and cooling will cause the nut to loosen leading to the arcing which will get progressively worse. You can try cleaning and tightening the terminal but then it should be tested for maximum output and excessive ripple. With one shorted diode, the maximum output you will be able to get will be very near one third of its rated capacity.