I sure hope their are some Ford experts out there that can help me. I have had four heater cores replaced in my !999 Ford F150 in the last four months. The dealer is telling me that they are failing due to electrolysis. They think that it is due to the new stereo system that i had installed three weeks prior to the first one failing. When they fail, my carpets get soaked and my windows fog. My stereo was professionally installed and includes 4 pioneer 6x9s, a 12" subwoofer, and two amps- a punch amp to push the subwoofer and a Alpine V12 4 channel for the door speakers. It is putting out wattage but nothing like some systems I have seen in fords like mine. They have not had any problems with their heater cores. I checked the grounds on the amps and they are clean and touching bare frame metal in the rear of the truck. I dont know what to think of it all. The dealer said I might need to run a ground back to the battery. However, all of the stereo installers here in town say that is not common practice and they have never had to do this before. If it were electrolysis wouldnt It eat up my plastic radiator too? and cause havoc in the rest of my engine? They said after they relpaced the last heater core, they pulled the fuse to the stereo system and tested the coolant. They were still getting a reading of 0.288 volts. Is this normal? Does anyone have any ideas or suggestions? The Ford dealer said I might just have to pull out my current stereo system. I am just frustrated with this whole thing. Any help would be greatly appreciated. When I tell people that the stereo is causing the electrolysis, they just laugh.

 

This is just a stab in the dark, but it came to mind when I read your post. If the amps are causing the problem, pulling the radio fuse probably wouldn't change anything. The amps are probably only wired to the radio for the turn-on power. The main power supply is usually independent. Maybe you could try unhooking the main power to the amps(???). I don't know, just my thoughts. Good luck!

 

My wifes CheFy has blown 5 this year. I had it tested for everything under the sun. Two dealer techs I spoke with told me that it should be virtually impossible for electrolysis to cause a heater core to fail in such a short amount of time. It should take several months to have any effect according to them.
Not sure I trust that, since I am on my 5th core. I have also been informed that dealers buy their heater cores from a central manufacturer and that this place builds them for all makes. The quality control of this supplier has recently undergone an overhaul and the current batches of cores on the market now are defficient in quality. That could also explain our problems......

Perhaps the first blown core was a fluke, and the rest of them have fallen victim to this quality problem from the vendor??