Collection: Blue Connectors (1.5–2.5 mm²)

Blue lug: the standard section for automotive electrical systems

The blue lug (1.5 to 2.5mm² section) is the most common in automotive electrical systems. It covers the vast majority of everyday uses:

• Wiring of relays (Bosch, Tyco, ISO)
• Power supply for additional lights (fog lights, spotlights, roof LEDs)
• Horns and warning signals
• Geared motors of moderate power (windscreen wipers, power windows)
• Wiring of car radios and low-to-medium power amplifiers
• Standard tow bar wiring harnesses

With an allowable current of up to 20–25 A on a 2.5mm² cable, it meets almost all situations except high power (winch, intense halogen spotlight, secondary battery — which require yellow 4–6mm²).

Choosing between red, blue, and yellow: the three-color rule

The ISO 2770 color code for crimp terminals is simple and universal:

• Red = 0.5–1.5mm² (thin cables, signals, indicator lights, small accessories)
• Blue = 1.5–2.5mm² (standard cables, common accessories, relays)
• Yellow = 4–6mm² (heavy cables, high power, secondary battery, winch)

Matching the lug to the cable section is imperative:

• Lug too small → will not crimp correctly, the cable will slip and lose contact
• Lug too large → will not hold mechanically, leading to play and eventual oxidation

All types available in blue

• Ring terminals (M5, M6, M8) for grounds and bolted connections
• Fork terminals for removable connections
• Faston terminals male and female 4.8mm (the relay standard)
• Bullet terminals 4mm for wiring harnesses
• Butt connectors for splices and repairs

Same complete range as red, in the versatile 2.5mm² section.