Reliable High-Power Controlfor when regular switches won’t work
Your high-power solution. When regular switches can’t handle high-current loads, adding relays can become a complicated and messy project. That’s where MGI steps in — our fused relay boxes provide centralized control and protection with minimal wiring involved.
Wiring is made easy. Each bosch-style 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. Our relay boxes are routinely tested, with relays rated 40A at 12 volts to ensure optimal reliability come race time. Produced only with GXL high temperature wire, with no-nonsense screw terminal strips for reliable input and output wiring.
Choose the Number of Relays
We understand that space is a valuable commodity in your rebuild or showcar. That’s why we’ve designed automotive relay boxes with your choice of 4, 6, or 8 relays. Each relay box has at least one 5-pin relay that can be wired for normally closed operation if needed.
MGI relay panels 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.
Choose Your Fuses
Each MGI relay box comes with fuses tailored to your specific loads. Don’t know what fuse sizes you need? Don’t worry — MGI uses an industry standard, tried-and-true formula to provide recommended fuses sizes for your individual loads. A similar approach is used to calculate the main fuse size.
- Simply enter your current load for each relay into the calculator
- and indicate whether it is a motor load.
With this information, MGI will supply you with appropriate fuses unless otherwise selected.
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
Connect the black ground wire (with red ring terminal) to the auto chassis. Then, connect the control circuit wire(s) to your switch inputs, with outputs connected to the appropriate screw terminals.
Connect your loads to the appropriate screw terminals. Ground your loads. See the 4, 6, and 8 relay box diagrams above. In addition to regular N.O. circuits for each relay, the RCP4 has 1 optional N.C. circuit, the RCP6 has 2 optional N.C. circuits, and the RCP8 has 3 optional N.C. circuits.