High-Power Relay Controlwhat makes a relay bank & harness kit special
40 amp SPDT relays are a reliable solution to high-power accessory control. Easy-to-use socket bases are pre-wired with high-temperature GXL and premium stranded copper — install the relays with ease and confidence.
Rearrange, separate, and combine. an MGI relay harness is versatile, which makes it an ideal solution for cars, trucks, boats and more. Add or substract any number of relay bases with ease. SPDT relays with both a normally open (N.O.) and normally closed (N.C.) output gives you greater control of your accessories.
Choose the number of relays and their corresponding breaker sizes using our interactive builder. It’s that simple. You’ll be powering your 12v accessories in no time.
Relay Harness Featuresuse our interactive builder to customize your automotive relay harness
Choose the Number of Relays
We know that space is valuable in your car, truck, boat or off-road vehicle. That’s why we’ve designed power control harness sets with your choice of 3 to 6 relays, each rated 40A at 12 volts. It’s that simple.
Unsure of how many relays you need? Our interlocking relay bases lets you add or subtract any number of relays with ease.
Choose Your Breakers
Each MGI relay bank comes with breakers tailored to your specific loads. Don’t know what breaker sizes you need? Don’t worry — MGI uses an industry standard, tried-and-true formula to provide recommended breaker sizes for your individual loads.
- Simply enter your current load into the calculator
- and indicate whether it is a motor load.
With this information, MGI will supply you with an appropriate breaker size unless otherwise selected.
Wiring Made Easy
Each relay harness comes with lots of wire for both inputs and outputs. After mounting the relay harness in your location of choice, use the relay socket diagram as a guide to wiring your power source and loads.
- 40/40A changeover relays
- 5 Pin wiring with N.O. and N.C. outputs
- Interlocking bases
- Custom sized branch breakers
- Your choice of breakers sized between 5 – 30A
- Easy push button reset
- 2’ of GXL #14 AWG colored wire for each breaker input
- 5’ of GXL #14 AWG colored wire for each relay N.O. output
- 5’ of GXL #18 AWG white wire for each relay coil positive
- All necessary crimp terminals