JPD

I really have no other details, but I think it is somewhere between the liftgate and the roof area where the wiring must pass around a sharp edge under the rubber material.

So far no problem, but it took 2 weeks the last time, also I wonder if the new wire will also chafe. Just in case, I now carry a jump starter under the driver's seat. No need to wait for ford roadside, I'll just charge it myself, bring it back when convenient for me, no need for further documentation of a problem. But lets hope there is no further problem. I love the car!

first fallure after 2 weeks, 600 miles, no known battery drain (lights left on etc.) had Ford roadside assistance tow car to dealer. They could find no problem and assumed it was a bad battery which they replaced. second failure after 4 weeks, 1200 miles. Again had car towed to Englewood (FL) Ford. They surmised that this was not a simple bad battery problem and i advised them of the problems others were having. They had no other dead C-maxes, but they have not sold that many. At the advice of this forum, I also called Ford Customer service in order to make them aware that this is not an isolated problem and , please, take it seriously and find a solution or maybe I need a buy-back. after a few minutes on hold i was asked if I wanted a buyback BUT this is not to be construed as an offer of one. I replied I really wanted my car fixed if possible. I was told I would get a call from Ford in two business days with some sort of solution. I never received that call, probably because my dealer called back to tell me that the problem appeared solved. The service technician explained the chafed wire, etc. to me, and at that point I was just so delighted to get the car back I didn't ask for any more info. Englewood Ford's service department was stellar as far as I'm concerned, I couldn't give them any higher accolades and i wouldn't want them barraged with calls or cause them any trouble. Since it was a Ford field engineer who knew the problem was in wiring around the liftgate, I don't see why calling Ford at this point wouldn't yield results. I think they only very recently discovered this problem's solution. This may also explain that what i presume is the same set-up in the Fusion Hybrid hasn't resulted in but a few battery failures, because the Fusion doesn't have a liftback.

ONE OTHER THING, THE WIRING IN THE LIFTBACK BECOMING CHAFED ALSO EXPLAINS THE FLICKERING OF TAILLIGHTS SOME HAVE EXPERIENCED. POSSIBLY IT TAKES A NUMBER OF USES OF THE LIFTBACK TO CHAFE THE WIRING, EXPLAINING WHY IT TAKES 2 TO 4 WEEKS FOR THE PROBLEM TO OCCUR. AFTER THAT ANY LIFTBACK USE WOULD REPEAT THE BATTERY DRAIN. I ONLY USED THE LIFTBACK A FEW TIMES AND IT HAPPENED TO BE AFTER USING IT THAT THE NEXT MORNING I HAD MY SECOND DEAD BATTERY.

Thanks to this forum and someone mentioning wiring harnesses, my Ford service department took this problem seriously from the second time I had a battery failure. The first time they replaced the battery, having not found any other problems. a Ford field engineer happened to be visiting the service department the last day my car was there, the deadline before considering a replacement or buy back etc. The field engineer said the problem is in the wiring around the liftback or a door. Sure enough, a wire was "chafed" i the liftback causing a short circuit that activated a "module' (?) that caused said module to stay on and drain the battery. Wiring repaired, problem solved hopefully. in any event, the problem and solution are documented and should there be further issues, they will be resolved. Also they were appreciative of my input, most of my info coming from this forum since they have lately had a few more mysterious dead batteries. i hope this puts this vexing problem to rest and we can all enjoy our vehicles!