[LimaCharlie]

Electrolysis is one of the main reasons for heater core problems. Poor electrical grounds, low coolant levels, and poorly installed aftermarket electronics can all cause electrolysis.
For everyone with heater core issues......have you checked the level of your coolant lately? Do you have any aftermarket electronics (i.e. sounds systems) installed in your car? I'm curious to know if these are trends with heater core failures.

Here are some links on what I'm talking about:

http://www.aa1car.com/library/coolin..._corrosion.htm

http://www.4s.com/Upload/Four%20Seas...ECTROLYSIS.PDF

http://macsworldwide.wordpress.com/2...-electrolysis/

http://www.4s.com/Upload/Four%20Seas...EPLACEMENT.PDF