The brand new 2019 Mazda 3 is one of the most technological advanced, sophisticated, and premium feeling cars in its segment. Interior materials are top notch and GT trim vehicles like our customer's here come loaded with a ton of advanced features! We have been installing dash cams at local Mazda dealerships for a few years now, and found out that this new generation Mazda 3 poses a new challenge for hardwire installation.
The previous BM/BN/3rd Generation Mazda 3 was an interesting car as it came with a constant power 12V outlet from the factory under the armrest. Many dash cam users would leave their camera plugged into there and come back to a car with a completely drained battery. This was unlike any other Japanese car manufacturer as most prefer ignition switched outlets. For that reason, we recommended hardwire installs for all 3rd gen Mazda 3 as you could add a voltage cutoff device or just hook it up for accessory power.
With this new generation, Mazda has taken it one step further and only included constant power fuses in the passenger compartment fuse box. This fuse box is located in the driver's side footwell and is easily accessible but may not be all that useful for hardwiring a dash cam as it will also result in fully draining the battery as voltage cutoff won't be activated on many hardwire kits without a proper ignition switched signal.
There are a few ways around this issue:
- Phantom ignition power modules such as the PAC IGN-1
- OBD style hardwire cables such as the Power Magic EZ (for Blackvue)
- Using a multimeter to find an ignition switched wire you can tap off of
If you are tapping into modules and other wire harnesses in the vehicle, it's important to use a multimeter and not a test light. You want to make sure there is the correct voltage (12V) and ensure that you're not adding load to the module as that could cause damage to an expensive component. Test lights work by lighting up a bulb which does add a load to a potentially load sensitive circuit.
It's also worth noting that better hardwire kits like the Thinkware TWA-SH will have in-line fuses already (typically around 3A). If you would like, you can also build your own fuse with a couple of spade terminals and a blade fuse. Dash cams don't need much current to run although battery packs typically charge at over 5A so you need to be especially careful with those.