A21ASP12VDC1.9D

Relay Automotive Overview

The A21ASP12VDC1.9D is an automotive relay manufactured by CIT Relay and Switch, designed for high-current switching applications in vehicle electrical systems. It features a single-pole single-throw normally open (SPST-NO) contact configuration, providing one Form A circuit path. The coil operates at 12VDC with a power consumption of 1.9W, drawing approximately 158 mA. The contacts are rated for a maximum continuous current of 40A and can switch voltages up to 75VDC. The unit utilizes quick-connect terminals for mounting and is built to withstand operating temperatures ranging from -40°C to 125°C.

Relay Automotive Feature Summary

• SPST-NO contact arrangement for simple on/off control
• High current capacity suitable for heavy automotive loads
• Sealed construction for environmental protection
• Quick-connect terminal style for rapid installation

Relay Automotive Applications

• Automotive lighting circuits
• Heater and blower motor control
• Fuel pump activation
• General vehicle accessory power distribution

Relay Automotive Procurement Notes

Verify the specific part number suffix against official CIT Relay and Switch documentation to ensure correct coil voltage and contact rating alignment. Confirm that the required current load does not exceed the 40A continuous rating. Check for RoHS compliance requirements if applicable to your assembly. Ensure the mounting base matches the quick-connect terminal specifications before ordering.

Relay Automotive Selection Notes

Select this component when a robust SPST-NO relay is needed for 12VDC automotive environments. The 40A rating supports high-power devices such as fans or lights. Consider the 1.9W coil power for driver circuit design. Verify that the operating temperature range meets the specific location constraints within the vehicle chassis or engine compartment.

Relay Automotive Part Context

This model belongs to the CIT automotive relay family, characterized by sealed housings and high durability standards. It is engineered for reliability in harsh under-hood conditions. The series typically includes variants with different coil powers and contact arrangements to suit diverse vehicle electrical architectures and manufacturer specifications.

Relay Automotive Replacement Considerations

Cross-reference with other CIT models sharing the same footprint and terminal layout. Ensure substitute parts match the 12VDC coil voltage and 40A contact rating. Verify that any alternative maintains the SPST-NO configuration and compatible switching voltage limits.