OEX ACX1944RBL Mini Relay 12V Normally Open 70A - Resistor Protected, Sealed

OEX ACX1944RBL 12V 70A High-Current Normally Open Mini Relay 4 Terminal 9.5mm Power Pins Resistor Spike Protection IP67 Single Unit

The OEX ACX1944RBL is a 12V, 70A normally open mini relay with resistor spike protection, supplied as a single unit. Rated at 70A, this is a high-current relay suited to winches, high-draw accessories, starter motor bypass circuits and other demanding switching applications. It uses a four-terminal configuration as a high-current normally open relay there is no normally closed contact (87a). Terminals 87 and 30 use larger 9.5mm blade terminals to handle the higher current; coil terminals 85 and 86 use standard blade sizing. IP67 sealed housing with a fixed moulded mounting tab. Covered by a one year warranty.

Product overview

Standard 40A mini relays (such as the ACX1940RBL) use 6.3mm blade terminals throughout and include five pins with both normally open and normally closed contacts. The ACX1944RBL steps up to 70A with two important differences the power-carrying pins (30 and 87) use larger 9.5mm blade terminals rated for the higher current, and the normally closed contact (87a) is omitted, resulting in four terminals only. Wiring for this relay must use connectors or lugs sized for 9.5mm blades on the power pins; the coil terminals (85 and 86) use standard sizing.

At 70A the ACX1944RBL suits winch and recovery equipment power circuits, high-draw lighting switching, starter motor bypass and isolation circuits and high-capacity auxiliary power feeds that exceed the 40A rating of standard mini relays. The resistor spike protection suppresses the voltage spike generated when the relay coil is de-energised, protecting ECU and control module outputs used to trigger the relay. The IP67 sealed housing provides full protection against dust and temporary water immersion for underbonnet and exposed mounting. The moulded mounting tab is fixed into the relay body rather than removable.

Features and benefits

70A rating: High-current relay suited to winches, high-draw lighting, starter motor bypass circuits and other demanding switching applications exceeding the 40A rating of standard mini relays.

4-terminal configuration normally open only: No normally closed (87a) contact. Terminals are 85 (coil negative), 86 (coil positive), 30 (common) and 87 (normally open). If both NO and NC contacts are required, a change over relay is needed.

9.5mm blade terminals on pins 87 and 30: Larger terminal size to carry the 70A rated current through the power circuit. Ensure wiring uses connectors or lugs sized for 9.5mm blades on these pins. Coil terminals (85 and 86) use standard blade sizing.

Resistor spike protection: Suppresses the voltage spike generated when the relay coil is de-energised, protecting ECU and control module outputs in the triggering circuit.

IP67 sealed housing: Fully protected against dust and temporary water immersion, suited to underbonnet, exposed and marine-adjacent mounting positions.

Silver tin oxide contacts: Reliable switching performance with excellent contact life at high current.

Moulded mounting tab fixed: Mounting tab is integrated into the relay body rather than removable.

Single unit: For individual installations or replacements.

One year warranty: Covered by a one year OEX warranty.

Technical specs

Frequently asked questions

Why does this relay have 4 terminals instead of 5? Standard 5-pin mini relays include both a normally open (87) and a normally closed (87a) contact. The ACX1944RBL is a high-current normally open relay only the normally closed contact is omitted, resulting in 4 terminals: 85 (coil negative), 86 (coil positive), 30 (common) and 87 (normally open). If both NO and NC contacts are required, a change over relay is needed.

Why are terminals 87 and 30 larger at 9.5mm? The 9.5mm blade terminals on pins 87 and 30 are sized to carry the 70A rated current through the power circuit. Standard 6.3mm blade terminals are not rated for this current level. Ensure wiring uses connectors or lugs sized for 9.5mm blades on these pins the coil terminals (85 and 86) use standard blade sizing.

What is the difference between this and the 40A ACX1940RBL? The ACX1944RBL is rated at 70A and uses 4 terminals with larger 9.5mm power pins, suited to high-current applications like winches and high-draw accessories. The ACX1940RBL is rated at 40A, uses 5 terminals including 87a, and has standard-sized blade terminals throughout. Select the ACX1944RBL for loads exceeding 40A.

What does resistor spike protection do? When a relay coil is de-energised it generates a voltage spike that can damage sensitive electronics. A resistor across the coil terminals suppresses this spike, providing protection for ECU and control module outputs used to trigger the relay.

Is this relay suitable for underbonnet use? Yes. The IP67 sealed housing provides full protection against dust and temporary water immersion, making it suitable for underbonnet, exposed and marine-adjacent mounting positions.