94 Escort heater core

I have a 94 Escort wagon that is eating heater cores. Original one went two years ago. I replaced it with a Ford heater core that lasted exactly one year. Second one replaced with one from the local auto parts store. That one lasted 10 months. What am I doing wrong?????? I had the cooling system professionally flushed and cleaned after doing the heater core for the second time. The original lasted nearly 10 years. 2nd one one year. 3rd one 10 months.

Thanks for any help or insight.

Jeff

Was the radiator cap replaced?

No, I didn't replace the radiator cap. Never really thought of it. Someone mentioned a mild electrical current in the coolant system as the cause but I can't seem to find anyone who's ever heard of that problem or how to correct it. I'm going to replace it with an OEM core AGAIN and I'll replace the cap as well. Heck, I'll replace anything to avoid have to tear the dash out a 4th time.

Might be a bad ground causing electrolysis. See link:

http://members.shaw.ca/autocheck/electrolosis.htm

HMMmmm..cores going...Are they corroding? Can't see them bursting as they are stronger than other components in the system.
Electrolytic action? bad ground as mentioned?
Running a good 50/50 af/water mix.?

Nothing galvanized in the system is there?..A piece of galvanized pipe as a joiner maybe?

IF the cores are corroding..couldn't you take a sample of the af and test it?.

I can't see a core being corroded that quick by anything really..

A call/email to a rad.mnfr./cooling system expert might help.Internet search?

Any possibility that something is contaminating the coolant? Minute head gasket leak?

I'd be flushing it..50/50 af.,water..testing the coolant.Retesting the coolant.