We just got a 65k miles Cmax 2013 and as you might as well guessed it, it has the drain issue. Now to be honest I did not know about this issue prior to buying it and we took it to Form, 500$ later a new 12v battery and battery plug, what ever the hell that is, we were told the car is fixed. We drove the car from Montreal to San Diego with no issues. Now every few days the car decides to not turn on. As an engineer I decided to figure out the issue myself. If you measure the power on the low voltage battery is 4.3v and draining still. Nothing in the car was on so yes F79 is what made sense to pull first. The voltage stopped dropping, after checking more, turns out that ACM is draining the power. The issue is that this part is buried under the dam dash, so no go for simple fix. However if we look at fuse 79 is controls - Voice control module, radio, navigation system, DVD player, CD changer, door lock button . I dont understand what door lock button is because Fuse 66 also controls Driver's door lock, double locking . In any case the simple solution at this point is to compliably disable F79 when they car is off, now this sucks as you get to lose all your cool stuff, like presets i guess. But i would rather not have presents than no power on the car. In any case this relay fuse will do the trick Amazon Link . You will have to replace the 30A with a 15A, than remove fuse 79. Connect left pin from Fuse 79 to line 30 on the relay. Than Fuse 61 to Relay 30. This way the relay will turn on when the cart starts. And the ground to ground. This will now turn on fuse 79 only when the cart starts.
