ONLINE LED STORE True MODS Bosch-style 4-Pin 12V Relay Kit — 6-Pack, 30A Fused Harnesses with 14 AWG Leads

True MODS 6-Pack Bosch-style 4-pin relay kit delivers six 12V SPST 30A relays with integrated fuse sockets and 30A blade fuses for reliable automotive and marine switching.

This six-piece relay set from ONLINE LED STORE pairs Bosch-style 4-pin SPST relays with harnesses that include built-in fuse holders and pre-wired 14 AWG heavy-duty leads. Designed for 12V systems (up to 14V), each relay supports up to 30 amps at the switched contact and uses a common Bosch footprint for easy replacement or installation. The harness wires are color-coded for quick identification, helping reduce wiring mistakes and speeding up installs for accessories like lights, horns, pumps, or auxiliary devices.

What connections come pre-wired on these relays?

Each harness is assembled with four clearly labeled wires that match the Bosch 4-pin relay terminal layout. The integrated fuse socket sits inline on the main feed for added circuit protection.

• Black: ground (coil terminal 85)
• Red: power input/main feed (contact terminal 30)
• White: coil trigger input (terminal 86)
• Blue: normally open switched output (terminal 87)
• Includes a 30A blade fuse seated in the built-in holder for each harness

How much current and voltage can these relays handle?

These relays are rated for 12V DC systems and are safe to use in applications up to 14V, covering standard vehicle and many marine electrical setups. The switching contact is rated at 30 amps, suitable for common accessories without overloading the relay when properly fused.

• Operating voltage: nominal 12V, maximum 14V
• Switching capacity: 30A on the output contact
• Included 30A blade fuses protect wiring and accessories
• Heavy-duty 14 AWG main wires reduce voltage drop on high-current circuits

Why use a fused relay harness instead of wiring directly?

Integrating a fuse socket into the harness places circuit protection at the power source, which is safer and simplifies troubleshooting. It also keeps the relay and fuse consolidated, cutting install time and reducing clutter under dashboards or in engine bays.

• Fuse located at the feed minimizes unprotected wiring length
• Pre-crimped, color-coded wires speed up connections and ensure correct terminals
• Compact harness design fits tight spaces and standard relay sockets
• Package of six relays keeps spares on hand for future upgrades or replacements

Who is this for? Technicians, DIY vehicle owners, fleet maintainers, and hobbyists who install or upgrade 12V accessories will appreciate these True MODS relay kits. They suit anyone needing multiple reliable relay assemblies with onboard fuse protection for lighting circuits, auxiliary pumps, winches, horns, or custom electrical projects. The Bosch-style footprint and color-coded 14 AWG wiring make these kits a convenient choice for repeat installs, service replacements, or when you want a compact, safer wiring solution that reduces installation time while improving circuit protection.