Project SC300 Road Racer: Part 26 – It’s Getting Hot in Here, so Chillout!
a wiring diagram showing the blower, cooler, relays, and etc.
Even a quick paper and pencil wiring diagram sketch can do wonders for getting things executed quickly.

RP is the Racepak Smartwire, and I already had planned for future / spare circuits with a connector waiting to be wired. A switch would control one of these spare outputs from the Racepak. While the Smartwire does have 20A outputs, and you can tie two of them together to provide 40 Amps, all of that was already used in other ways, so I had to do something a little different.

As you can see, I have a standard automotive relay that will be used to switch the big power to the Quantum Cooler. But the coil of the relay itself draws very little current, and I want the blower to be powered any time the cooler is running anyway. So, I decided to attempt to maim to flying creatures with one implement. The output of the Racepak would energize the relay coil and also power the blower. Sweet.

On the big power side, I got one of those massive 40A marine fuse holders to go with the massive 8-gauge wire that the Chillout cooler’s harness comes with. I put the fuse on the power-source side of the circuit. If for some reason the relay internally shorts or melts down, the fuse will blow and things are great. If the fuse was on the device side of the relay, and the relay had a problem, the car would burn down. Now, sure, something could happen between the fuse and the battery, but as you’ll see there’s only a foot or so of wire there. The closer the fuse can be to the power source, the better (and faster) it will work.

Alright, the plan is in place. Let’s get to it.


ring terminal with un-shrunk glueline over thick wire that has a black and blue stripe pattern
The first step was to add ring terminals to the big wires that would attach to the battery.

The power harness that Chillout Systems provides with the Quantum Cooler is really, really long. So there was more than enough extra to trim things to the right length and have some spare pieces to go between the relay and so forth.

As with the blower, Chillout is very explicit about not reversing the polarity of the power and ground, as it will fry the internal inverter. Be extra cautious to remove the black and blue colored insulation to determine which is the power (red) and the ground (black).

I used a little bit of glue line heat shrink to both keep the pretty Chillout insulation in place and to help keep things neat and tidy.


marine fuse holder and heat shrinked wire with spare fuse and barrel splice sitting in background
You can get a big fuse holder from Chillout systems, but they don’t sell the barrel splice that you’ll want.

The fuse holder comes with a length of 8-gauge wire, but you have to attach that to the relay on one side, and to the battery on the other side. I used this butt/barrel splice connector in the background to attach a length of wire that I cut from the harness to the fuse holder, and made sure to put glue line over that, too. A ring terminal on the end and then I had the battery side of the setup all done.

1 comment

  1. That’s cool, but not $2500 cool. Damn! The collective sum of all my winter upgrades will come in comfortably south of that. Hopefully the price comes down as the tech matures.

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