vballvic

I have a 2017 C-MAX Energi. Recently I discovered a coolant leak which I have tracked down to what appears to be the auxiliary heater core. It's a black box located in front of the passenger wheel well with radiator hoses and an orange high-voltage cable leading to it. Unfortunately the leak appears to be coming from the middle of the housing and NOT from the hose connections. I don't see an easy way to fix the leak. I looked into buying a replacement part but the heater core (part # FV6Z18K463E) is about $600-700 shipped. Being that I never use the heater when in EV mode and the heat is generated by the engine when in hybrid mode, I'm thinking of removing the aux heater core and bypassing the coolant circuit with some radiator hoses and connector/clamps. Anybody have any experience with removing or at least replacing the heater core? It looks like it can be accessed by removing the wheel well liner / inner fender. I can't find any online tutorials or videos on this particular repair / topic. Some foreseeable issues are: Risks of handling the high voltage cable: The cable is connected to the rest of the system via a harness clip near the coolant reservoir and should be easy enough to simply disconnect. I think it should be safe to assume that there is no power when the heater is off, especially with the car off. Even if there is voltage, I think it should be safe enough to unclip the cable and cap off the live-end with some electrical tape. The system might see the heater core missing and might throw some trouble codes. I guess the question is how badly do you think the vehicle will react to this? Will it disable the high voltage system completely making the car undrivable? Will it just throw an error code notifying the driver of the "issue"? Or will it go unnoticed until someone attempts to use the heater in EV mode? Is there a fuse to pull to disable the system from trying to activate the aux heater core? Any suggestions or feedback welcome.

@bookemdano: I am the third owner of a 2017 Ford C-Max Energi. I received the letter from Ford regarding the "Customer Satisfaction Program 21B09" and it appears that they are offering to cover labor of install if I pay for the modem. I called 2 of the nearest dealerships in NJ: 1 said they have heard of this but have no information on how to do the install. The other (Haldeman Ford) quoted me "approximately $700" for the modem. Not so sure it's worth it for $700. May need to try a 3rd dealership.