Fixing Electrical Gremlins

Although we had a successful result at the DC ProSolo last week, it wasn't without issue. The clamp going to the negative terminal of the battery had vibrated loose after all those launches causing all kinds of weird TPS and engine misfire problems. This wasn't the first time this happened so to fix this issue permanently it was back to SJF Performance to find a solution.

175A @ 600V Battery Quick Connect Kit

I picked up a Battery Quick Connector kit rated at 175A at 600V from Amazon.com  that's normally used for winches or fork lifts and wanted to see if SJF could figure out how we could wire this up on my car. Since I don't have power at Bumblestook's storage, I take the battery home after every event to charge and I wanted a way to easily disconnect the cable but also provide a stable and secure connection.

Old battery setup with inline kill switch

Battery terminals clipped off - 5/22/2016

The first order of business was to remove the terminal ends off the existing wiring. The ground going to the chassis was a 2-gauge wire but ended up being a 4-gauge wire after the kill switch and there are two 4-gauge wires connected to the positive terminal for the starter and the rest of the car electronics. The battery quick connector was designed for 2-gauge wire but you can't fit two 4-gauge wires into it so Steve had to figure out something else. Thankfully he had a spare junction box sitting around (in yellow too!) and the two existing 4-gauge positive terminal wires were hooked up to it along with one more new 4-gauge wiring going to the quick connect. It was also fortunate that Steve had this gigantic crimping tool that could be used to crimp connectors onto these thick wires.

Connector crimped on for the junction box

All positive side wires connected to junction box

For the ground wire, we didn't like the existing ground on there so Steve replaced it with a new 4-gauge wire with fresh terminals crimped on that didn't have oversized holes for a perfect fit. The other end of the ground wire went into one of the quick connect ends as well.

New ground wire installed

On the battery side, we unbolted the SAE automotive battery terminals from the Shorai battery and instead bolted on 4-gauge wires with new ends to the other quick connect box. The result was a clean and perfect connection that's super easy for me to disconnect whenever I need to pull the battery out or when I'm towing long distances and don't want any draw. I also got the dust caps for each side of the quick connect to avoid any accidental shorts when the two sides are disconnected. The car started up perfect with a clean reading on the voltage by the ECU.

Quick connect installed - 5/22/2016

Shorai with quick connect at home - 5/22/2016

We also flushed the diff fluid and inspected for any potential problems after the ProSolo and so far everything seems good. No differential pieces came out of the drain plug so we've got a green light to test the car this weekend before heading to Toledo next month.

SJF Performance - 5/22/2016