4 Relay Panel – Upgraded 12GA Wiring with Flyback Diodes **ON SALE**

$149.00 (USD)

Built with heavy-duty 12AWG RELAY WIRES and FLYBACK DIODES.

Save 30% while supplies last.

  • Motor Loads (fans and pumps): rated 12A @ 12vDC
  • Resistive Loads: rated 24A @ 12vDC
  • 4 x pre-wired SPST relays rated 40A with built-in smart LED fuses that glow when blown
  • Comes with main feeder and main fuse
  • Each individual relay can be wired for either positive or negative switching

In stock

  • Choose your own fuse and feeder cable sizes.


    Dust-tight and weatherproof IP66 rating. See our RCP enclosure page for more details.

BULK ORDERS – please contact for availability.


Automotive Relay Panels by MGI SpeedWare
use our interactive builder to customize your multi-relay control panel

mgi speedware relay panel kits
automotive relay panel

Pre-Wired Relay Box with Built-In Fuses

An MGI relay box can control high-current car accessories that regular switches can’t handle. Have electric motors, spotlights, or high-current resistive loads? A relay box will do the trick. Comes with fused relays, a main fuse, and main feeder conductor.

  • Can handle up to 24A resistive loads, and up to 12A electric motor loads (fans and pumps).
  • Lightweight and compact aluminum construction
  • No messy wiring — the SPST relays are pre-wired and ready to go
  • Every individual relay allows for negative switching
  • Proudly designed and assembled in North America
  • #6 bolt-size screw terminals are labeled for easy wiring


Innovative relays with built-in fuses greatly reduces the amount of wiring needed. SPST relays are rated 40A at 12vDC, with smart LED fuses that glow when blown. What’s more, each relay and fuse can be easily replaced if needed.

automotive relay panel with terminal strips


High-quality barrier screw terminals makes wiring quick and easy, especially with fork / spade connectors. Each screw is clearly numbered – simply use the included wiring diagram to make your connections.

automotive relay panel rear


MGI SpeedWare relay boxes are designed to reduce custom wiring as much as possible – that’s why our boxes are pre-wired and ready to go. All you need to do is connect a power source, switches and loads to the appropriate screw terminal.

Modular Relay Panel Wiring Diagrams
how to install 3, 4, 6, and 8 relay modules


Battery Power

relay box power

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

relay switches

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.


Outgoing loads

relay box wiring

Connect your loads to the appropriate screw terminals. Ground your loads. See the 3, 4, 6, and 8 relay module diagrams above.

Answers to Popular questions

Why buy a fuse & relay panel?

When rebuilding, restoring, or refurbishing your vehicle, you’re bound to need electric pumps, fans, spotlights and more. These high-current devices will damage regular ignition key switches or low-current switch panels — however, an electromagnetic switching relay panel will give you the safe and reliable control you need.

Can this relay box operate “normally closed” devices?

No. Our SPST relay boxes are designed for standard normally open (N.O.) loads only. However, our specialty SPDT Bosch style relay boxes can power devices that are normally closed.

some popular relay panel projects

Negative Switching

Some devices are designed specifically for negative ground switching. With our SPST relay panels, every individual relay allows for negative switching. Simply connect your switch between the appropriate ground terminal and chassis. Note: switches with LEDs will not function properly with negative switching.



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Before finalizing your purchase

It is important to familiarize yourself with the MGI panel Installation Manual. Not only does this help you to select the appropriate options for your race panel, it will enable you to tackle any troubleshooting issues with confidence.