We are still working on our 350Z electric project, today we pick up right after installing the thermistor expansion module.
Installing Fusion Relay Panel
Will started with hoses and moved to mount the fusion relay panel for the high voltage system. He chose to fix it behind the front seat. We got a body panel that we had to cut our fuse and relay panel into the wires to enable us to drop down right on top of our backbox to meet up with the bulkhead connector.
After cutting the body panel, Will installed the final fusion relay in the back of the panel, and then he made a lovely quarter-inch loom that went through the grommet holes, allowing us to conceal all the wires in the underside of the car and run them up to all 12-volt components. Installing it at the back of the driver's seat would enable us to quickly service any fuses and relays.
Different wires from the fusion relay panel go in different directions. One loom goes to the drivetrain radiator pump, the second goes to the chademo connector charge port and onboard charger, and the third moves to 102 pin on the side of our rear battery box.
Preparing Back Box
The next and most important job was to work on a backbox featuring a bunch of batteries. Each battery requires its parallel cells to be monitored for their voltages. So, the VMS can ensure that not too much current is being drawn and the batteries are in good health.
We had to install mil-spec connectors, a receptacle, and a connector to take all the leads outside the rear box and run them up to the front box.
The two connectors on the side of the backbox will allow us to have a quick disconnect in order to drop this box down if we ever want to service the relays or fuses that are inside of this box. We had 39 wires per harness that we needed to pin to each of these bulkhead connectors.
This whole box is quickly disconnectable. We cannot only drop it and service the fuses and relays but can also upgrade the batteries if we want to.
Subsequently, we crimped the pins into the bulkhead connectors. We had gone ahead and labeled all the leads. We also had to fix one more connector on the other side of the box before painting and setting it into the car.
The battery box holds four of our modules as well as our pack fuse and high voltage component fuses such as battery heater, cabin heater, AC compressor, and the charge fuses. It also holds our pre-charge fuse, tilting our pre-charge resistor, high voltage contactors, and actual BMS.
After the box was fully loaded, we needed to fix it, connecting all the looms and wires to different car devices. It was actually a test fit to plan out our route to cables. We smacked it against the machine, and it fits snugly. With the backbox fitted and the looms available, we can now route them and button everything up to get it all nice and clean.
Check it out for yourself in the video below!
That’s it for this episode! Next week we will continue our work on the backbox and share the changes we have made.