SongChuan 801H-1C-S 12VDC 10A 12VDC Power Relay 5Pins 1PCS #MO

Automotive · Relays · SongChuan 801H Series · 12VDC Coil

What Is the SongChuan 801H-1C-S Relay?

The SongChuan 801H-1C-S is a 5-pin electromagnetic relay with a 12V DC coil and SPDT (Single Pole Double Throw) contact configuration rated at 10A. It has one normally-open (NO) contact, one normally-closed (NC) contact, and a common terminal — giving you both switching modes in a single compact package. The "1C" designation confirms the SPDT form, and the 5-pin footprint follows the standard ISO mini relay layout used across automotive and industrial vehicle electrical systems.

In short: A standard-form-factor 5-pin automotive relay that can switch a 10A circuit using a 12V trigger — useful anywhere you need to control a moderate-current load from a low-current switch or ECU output.

Installation Tips and What to Know

1. Pin Identification on a 5-Pin Relay

On a standard ISO relay: Pin 30 = Common (COM), Pin 85 = Coil (-), Pin 86 = Coil (+), Pin 87 = Normally Open (NO — connected to 30 when energized), Pin 87a = Normally Closed (NC — connected to 30 when de-energized). The SongChuan 801H typically follows this layout, but always verify with your specific relay's markings.

2. Flyback Diode Protection

When the relay coil is de-energized, the collapsing magnetic field generates a voltage spike that can damage sensitive driver electronics (ECU, transistor switch, microcontroller pin). Always place a flyback diode (e.g., 1N4007) across the coil terminals (cathode to positive, anode to negative) if the relay is driven by a solid-state device.

3. Contact Material and Load Type

The 10A rating is for resistive loads. Inductive loads (motors, solenoids, coils) cause arcing on the contacts during switching, which erodes contact material over time. For inductive loads, derate the current by 50-60% or add snubber circuits across the contacts to absorb the flyback energy.

Key Specifications

Coil resistance, pull-in/drop-out voltage, and mechanical life ratings — consult the SongChuan datasheet or contact us for available documentation.

Typical Wiring Scenarios

• Headlight Harness Upgrade: The NC contact (87a) can run low-beam while the NO contact (87) switches to high-beam, all triggered by a single dash switch
• Cooling Fan Controller: ECU triggers the coil; the NO contact powers the radiator fan — keeps high current out of the ECU wiring
• Dual Fuel Pump Selector: Common (30) feeds engine; NC (87a) runs main pump; NO (87) switches to auxiliary — ideal for dual-tank setups
• Fail-Safe Lighting: NC contact keeps safety lights on; NO contact switches main load — if relay fails, safety lights remain powered
• Horn/Air Horn Toggle: NC (87a) for stock horn, NO (87) for air horn compressor — switch between them with one relay

Frequently Asked Questions

How do I test this relay before installing it?

Apply 12V DC to the coil terminals (85 and 86) — you should hear a distinct click. With a multimeter set to continuity or resistance, verify that Pin 30 connects to Pin 87 (near zero ohms) when energized and to Pin 87a (near zero ohms) when de-energized. If you get no click or the contacts do not switch, the relay coil may be open or the contacts welded. Test on the bench, not in-vehicle.

Can this relay handle a 24V truck electrical system?

No. The coil is rated for 12V DC. Applying 24V will overheat the coil and likely burn it out within seconds. For 24V systems, you need a relay with a 24V coil. That said, the contact side can switch up to its rated voltage (typically 14V DC for automotive, or higher for industrial variants) independently of the coil voltage — but always verify the contact voltage rating from the datasheet before switching higher voltages.

How do I identify a genuine SongChuan relay?

Genuine SongChuan relays have laser-etched markings (not ink-printed) with the part number, coil voltage, contact rating, and terminal identification clearly visible on the top face. The housing plastic should be uniform in color with no burrs or mold flash. Counterfeit automotive relays are common — they often have shallow or smeared printing and lighter-weight terminals. If in doubt, weigh the relay: a genuine 801H series relay will feel substantial, not flimsy.

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