Modern cars use a system called Canbus. CanBus is a Controller Area Network where a vehicle’s bus standards are designed to allow microcontrollers and devices to communicate with each other’s applications without a host computer.
In Plain English, when you tap into a fuse, that fuse might be linked to more systems than simply stated in your vehicle’s manual. If you have VIDA and a wire diagram for your specific car, I imagine you can trace to see what systems are linked where and to what other systems. Otherwise, it’s a bit of guess and check.
Two Examples:
1. On my first Dashcam install, I tapped into the 12V tunnel console for ACC (Accessory Power when Vehicle is Turned on). Nothing else was listed in manual on that fuse. When I parked my car at home, I would turn off the camera. Yet, every time I would lock the doors and enable alarm, I found the camera turned back on. Apparently through Canbus, the 12V tunnel console fuse is linked to the Alarm System. Thus, it was causing a conflict and I selected a different fuse.
2. On my mother’s vehicle, I installed a camera and selected a fuse I thought was “OK”.. It ended up being tied to the infotainment system (not mentioned in manual of course) through Canbus. It would cause the radio to be static. Once again, I moved the fuse and all resolved.
The Point I’m making is Empty Fuses may not be “empty”. You’d have to test to see whether they are ACC fuses (Accessory when car is on) or battery fuses (always active even when car is off). You’d then have to test to see if using them would cause conflicts.
Every car is different, but using the Heated Seats has posed no problems on my vehicle. Your manual doesn’t list any other systems, although it’s always possible that they are tied to something via Canbus. When hardwiring a car, you want to AVOID safety Systems, Tech, and Modules.
So if I were in your shoes, I would start with those 2 fuses as being the most benign and seeing if either one works.
Amperage: If the dealer lists the fuse amperage in the manual, I presume it to be accurate. For a Dashcam, the power draw is around .5 amps. So it doesn’t really require a robust fuse. The one I suggested is 15 Amps, but that’s only because it probably is a benign fuse. I imagine you could use a 7.5 Amp or higher, but I’ve always shot for 10 Amp or more if possible.
Normal Hardwire Kit:
In a fuse tap situation where you have two wires to hardwire (Battery and ACC), the bottom fuse would be the one pulled from the vehicle. The Top fuse would be the one protecting camera. In this instance, you’d put in a 5 AMP fuse up top.