Side-by-Side Comparison
Electrical & Ignition Standards
Automotive Blade Fuses vs. Automotive Relays & ISO Pinouts
Comparing 2 standards across 16 specifications. 16 key differences identified.
Comparing:
Automotive Blade Fuses
Automotive Relays & ISO Pinouts
Automotive blade fuses protect 12V/24V/48V vehicle electrical circuits, standardized under ISO 8820-3 / SAE J1284 into six physical form factors (Micro2, Micro3, Mini, Low-Profile Mini, Regular ATO/ATC, and Maxi) using universal color-coded amperage ratings from 1A to 80A.
Automotive electromechanical relays switch high-current vehicle loads (cooling fans, fuel pumps, headlights, starter solenoids) using low-current control signals, standardized under ISO 7588 into Mini (1-inch cube) and Micro form factors with standard DIN 72552 terminal numbering (30, 85, 86, 87, 87a).
Specification Comparison Table
16 Parameters| Parameter / Spec | ||
|---|---|---|
|
Governing Standards
|
ISO 8820-3 / SAE J1284 (Blade Type) / SAE J2077 (Miniature) | ISO 7588 / DIN 72552 / SAE J2544 |
|
Micro2 Fuse (Dual-Blade)
|
9.1 × 3.8 × 15.3 mm | 5A to 30A | Modern tight packaging standard | — |
|
Micro3 Fuse (Three-Blade)
|
14.4 × 3.8 × 18.0 mm | Dual circuits sharing one center power terminal | — |
|
Mini Fuse (ATM / APM)
|
10.9 × 3.6 × 16.3 mm | 2A to 30A | Common in 1990s–2010s vehicles | — |
|
Low-Profile Mini (APS / ATT)
|
10.9 × 3.8 × 8.7 mm | Ultra-short tabs flush with plastic housing | — |
|
Regular Fuse (ATO / ATC / APR)
|
19.1 × 5.1 × 18.5 mm | 1A to 40A | Universal benchmark standard | — |
|
Maxi Fuse (APX / MAX)
|
29.2 × 8.5 × 34.3 mm | 20A to 80A | High-current under-hood primary feeds | — |
|
Standard Operating Voltage
|
32V DC (Standard 12V/24V) / 58V DC (Specialty hybrid/48V mild hybrid) | — |
|
Form Factor Tiers
|
— | ISO Mini Relay (~28×28×25 mm) / ISO Micro Relay (~22×15×25 mm) / Maxi Relay |
|
Contact Switching Ratings
|
— | Mini: 30A to 50A at 14V DC | Micro: 20A to 35A at 14V DC |
|
Nominal Coil Voltages
|
— | 12V DC (automotive passenger cars) / 24V DC (heavy commercial trucks) |
|
Terminal 30 (DIN 72552)
|
— | Common High-Current Power Input (Fused Battery B+ feed) |
|
Terminal 85 (DIN 72552)
|
— | Relay Coil Ground / Trigger Return (connected to ECU or ground switch) |
|
Terminal 86 (DIN 72552)
|
— | Relay Coil Power (+12V ignition switch or control trigger) |
|
Terminal 87 (DIN 72552)
|
— | Normally Open (NO) Output — Energized when coil is activated |
|
Terminal 87a (DIN 72552)
|
— | Normally Closed (NC) Output — Energized when coil is unpowered (5-pin SPDT only) |