Fixing Cell Arcing
If a cell is sparking, determine the sparking area and removed cell to inspect closer. To see the sparking, you may need to look in through the blower compartment. See photo below.
To best see a sparking problem, cut an inspection hole in the duct. An inspection window can also be used to see when to clean.
A cell that is sparking randomly throughout is uncommon but could be caused by a film left behind from washing. If tobacco is not cleaned from a cell it can build up and cause random sparking. Diesel fumes can cause shorting problems and are not easily cleaned. High altitude can make the air cleaner more susceptible to sparking. The collector plates should be cleaned to the bare shiny metal (stained is okay).
We have seen continuous sparking (month+) burn away the high voltage contacts between the cells or at the power box. Most often sparking burnt a hole in the rear cell contact. When one cell sparks it draws a surge of current from the other cell. The surge causes a spark at the contacts between the cells. A cell with a burnt contact may also have a sparking problem elsewhere. A cell plate that that has experienced excessive sparking can become loose. The plates are mounted on rods and the surges cause sparking to erode the plate around the rod. Check for loose plates.
If a cell is shorted and keeps the LED indicator from coming on, then inspect for damage. A dent across several plates causing them to touch would be a simple short to find. A dandling ionizing wire can cause a short.
Here our photo shows the view of the cells through the blower compartment. If necessary use a mirror to locate the continuous sparking.