High-Power Automotive Controlfor when regular switches won’t work
Your high-power solution for when regular switches can’t handle high-current loads. Adding relays can become a complicated and messy project — our fused relay boxes provide centralized control and protection with minimal wiring involved. Ideal for all automotive devices such as spotlights, motors, pumps, and fans.
Wiring is made easy. Each automotive relay box comes with a red main feeder cable and labeled screw terminals. Use the Installation Manual and wiring diagrams to help connect your power source, switches, and loads. It’s that easy.
Quality is Guaranteed. Every automotive relay box is tested, with relays rated 40A at 12 volts to ensure optimal reliability come race time. What’s more, our relay boxes are built with GXL high temperature wire, and with no-nonsense screw terminal strips for reliable input and output wiring.
Modular Relay Panel Featuresuse our interactive builder to customize your multi-relay control module
Choose the Number of Relays
MGI modular relay panels are built with your choice of 3, 4, 6, or 8 relays. There’s no need for complicated and messy wiring — the SPST relays are pre-wired and ready to power your high-current devices. All you need to do is connect your switches and loads to the labeled screw terminal.
What’s more, every individual relay allows for negative switching, a unique feature among automotive relay panels. See the negative switching example for more details. Note: switches with LEDs cannot be used for negative switching.
But what makes an MGI relay panel truly special is our fused relays. Most fused relays are rated for 30A only — ours are uniquely manufactured to handle 40A. Every relay can also come with flyback diodes installed. The use of a diode in a relay circuit prevents voltage spikes from arising when the power supply is disconnected.
And yet with all these great features, MGI fused relay modules are remarkably lightweight due to their aluminum frame construction.
Choose Your Fuses
To make life easy, MGI relay panel modules come standard with pre-selected fuses for use with typical high-current devices. Want to choose your fuses instead? MGI’s interactive fuse selector makes it easy to order the relay panel you need. You can also input your loads — we use industry standard, tried-and-true formulas to provide recommended fuse and feeder sizes for your custom loads.
- Simply enter your current load for each relay into the calculator
- and indicate whether it is a motor load.
Modular Relay Panel Wiring Diagramshow to install 3, 4, 6, and 8 relay modules
Connect the red main feeder conductor to the car starter’s battery power terminal. Then, install the supplied main fuse and holder in the main feeder conductor between the starter and the power stud found inside the panel.
Switches & Grounds
Install a ground wire between the relay panel and the auto chassis. Then, connect the control circuit terminal to your switch inputs, with switch outputs connected to the appropriate screw terminals.
Connect your loads to the appropriate screw terminals. Ground your loads. See the 3, 4, 6, and 8 relay module diagrams above.