If you’ve purchased one of our radiator kits with single fans, then this is the fan harness you need to wire your new cooling fan up without headaches and reliability issues. After over 20 years of building radiators with electric cooling fans, we’ve leanred a lot about problems that can creep up in electric fan installs. The biggest problem, without question, is garbage fan wiring. It will cause you more misery than you can possibly imagine.
To save you from that fate, we’ve put together a killer single fan harness kit that has everything you need to quickly install your new electric cooling fan with a reliable setup that will last for years. The foundation of our fan harness kit starts with high grade 10 gauge wire.
Why 10 gauge wire? Well, did you know dropping the fan voltage from 13.8v to 12.0v will cut the fan CFM output by over 20%? The quickest way to drop the fan voltage between the battery and the fan is to use cheap wiring. All of our fans need 10 gauge wire to get the necessary amps to the fans without causing excessive voltage drop.
Next on our list of must-haves in our killer harness kit is the a sealed 40 amp relay, no Chinese $.75 relay that’s going to crap out in a few weeks. In addition, the relay has a Delphi Metripack sealed socket connector. If you’re not familiar with Metripack connectors, they are OEM connectors used on just about every GM vehicle on the road. They are sealed to keep moisture out and ensure the relay lasts essentially forever. We’re so sure of that the entire kit has a lifetime warranty on it.
To make sure your electrical system isn’t hammered when both fans turn at once, our harness has a delay relay, which delays the activation of the second fan by 10 seconds. This progressive activation system prevents a full 60 amps from hitting your electrical system at once. On cars with marginal electrical systems, this can make a massive difference.
The next item likely to cause you a lot of grief is the temp switch. Most are made from cheap steel and zinc plated to look like brass. The result: you’ll end up with a cheap temp switch that will last 6 months if you’re lucky. Knowing how important the reliability is, we spent months designing and torture testing this 187F temperature switch. With a high degree of confidence, I can say your block will likely rot out before you’ll need to replace this switch.
Last but not least is the fuse holder. You might be wondering how much of a difference a fuse holder can make and I often wondered that myself. I can tell you from experience: it makes a HUGE difference. Most of the cheap Chinese fuse holders are made with cheap 14 gauge wire and half-ass crimps that cause a ton of resistance. If that wasn’t bad enough, most are made from recycled PA-66 plastic. The result is a brittle plastic that melts way below spec.
To eliminate all of these problems, we use a 10 gauge fuse holder made with virgin PA-66 material using Delphi sealed connectors for both the wires and the fuse. This ensures you won’t pull over on the side of the road and find your fuse holder melted on a hot day or a long road trip.
To recap, our dual fan harnes includes everything you need to install your new electric fan setup:
– Dual fan harness with 10 gauge wire, sealed 40 amp relays and sealed relay holders
– Engineered brass 3/8″ NPT 187F temperature switch
– Installation kit including tie wraps, crimp connectors and mounting screws
– Lifetime warranty
– Sealed Delphi Metripack connectors that connect directly into all of our cooling fans