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Error code reference

Daewoo Air Conditioner Error Code ON LAMP Blink (8s, 1 times blink)

Outdoor coil sensor open or short circuit; unit continues working.

Daewoo codesDaewoo air conditioner codes

Outdoor coil sensor open or short circuit; unit continues working.

First step from the service manual

Check outdoor coil thermistor for open or short condition.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
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What ON LAMP Blink (8s, 1 times blink) means on a Daewoo air conditioner

The ON LAMP Blink fault code on a Daewoo air conditioner, indicated by a single blink with an 8-second interval, signals that the outdoor coil thermistor has developed an open or short circuit condition. The outdoor coil thermistor is a negative temperature coefficient (NTC) resistor mounted on the outdoor heat exchanger coil. Its job is to continuously report coil temperature to the control board so the system can manage defrost cycles, compressor protection, and overall refrigeration operation. When the control board detects a resistance value outside the expected range, either too high (open circuit) or too low (short circuit), it logs this fault.

An open circuit condition means the thermistor circuit has lost continuity, often due to a failed sensor element or a broken wire in the harness. A short circuit condition means the resistance has dropped near zero, which can be caused by damaged insulation, a pinched wire, or a defective sensor. Because the unit continues operating despite this fault, the control board is likely substituting a default temperature value or operating with reduced sensor feedback. This can affect defrost accuracy or coil protection but does not immediately shut the system down.

Diagnosis begins by disconnecting the outdoor coil thermistor connector and measuring its resistance with a multimeter. A healthy NTC thermistor will show a specific resistance at a known ambient temperature. A reading of near zero ohms indicates a short, while an infinite or open-loop reading confirms an open circuit. Inspect the wiring harness between the sensor and the outdoor control board for visible damage, corrosion at connector pins, or chafing against metal panels before condemning the sensor itself.

Source: manufacturer service documentation.

Common causes of ON LAMP Blink (8s, 1 times blink)

  1. 01

    Failed outdoor coil thermistor

    Part replacement

    The thermistor element itself has failed internally, producing a resistance reading that is either open (infinite) or shorted (near zero). This is the most common cause and is confirmed by measuring the sensor resistance directly with a multimeter.

  2. 02

    Damaged wiring harness

    Part replacement

    The wire connecting the thermistor to the outdoor control board may be cut, chafed, or pinched, breaking the circuit or causing a short. Visually inspect the full length of the sensor wiring for contact with metal edges or signs of rodent damage.

  3. 03

    Corroded or loose connector pins

    Wiring / connection

    The thermistor connector at the control board or sensor end can accumulate corrosion, increasing resistance and mimicking an open circuit. Disconnecting, inspecting, and cleaning the connector pins may resolve the fault without replacing the sensor.

  4. 04

    Moisture intrusion at the sensor connector

    Wiring / connection

    Water entering the outdoor unit can bridge connector pins and create a short circuit condition. Check for standing water or condensation around the connector and dry the area before re-testing.

  5. 05

    Faulty outdoor control board

    Part replacement

    If the thermistor and all wiring test within normal parameters, the input circuit on the outdoor control board may have failed, causing it to misread the sensor signal. This is the least common cause and should only be considered after ruling out the sensor and wiring.

See the test procedure for each cause

Frequently asked questions about ON LAMP Blink (8s, 1 times blink)

What does ON LAMP Blink (8s, 1 times blink) mean on a Daewoo air_conditioner?
This blink pattern indicates that the outdoor coil thermistor has been detected in an open or short circuit condition by the control board. The outdoor coil thermistor is a temperature sensor mounted on the outdoor heat exchanger that provides coil temperature data to the system. Importantly, the unit will continue to run despite this fault, but the sensor issue should still be addressed to maintain proper system protection and defrost performance.
Can I fix the outdoor coil sensor fault on my Daewoo air conditioner myself?
A knowledgeable DIYer can inspect the sensor wiring, check connector pins for corrosion, and test the thermistor resistance with a multimeter. If the thermistor itself has failed, replacing it requires sourcing the correct sensor for your specific model and re-routing it to the control board connector. If you are not comfortable working inside the outdoor unit or identifying the correct replacement part, a qualified technician should handle the repair.
Is it safe to keep running my Daewoo air conditioner with this error code active?
The unit is designed to continue operating when this fault is present, so immediate safety risk is low. However, running without accurate outdoor coil temperature feedback can reduce the effectiveness of defrost cycles and coil protection, potentially leading to more serious issues over time. It is best to have the fault repaired in a timely manner rather than ignoring it indefinitely.
How much does it cost to repair an outdoor coil thermistor fault on a Daewoo air conditioner?
If only the thermistor sensor needs replacement, parts typically cost in the range of $15 to $60 depending on the model, with professional labor adding $75 to $150 or more depending on your location. If the wiring harness or control board is also damaged, total repair costs could be higher. Getting a diagnostic quote from a technician before authorizing parts replacement is recommended.
Will resetting my Daewoo air conditioner clear the ON LAMP Blink fault code?
A power reset may temporarily clear the displayed fault, but the code will return if the underlying thermistor or wiring problem has not been resolved. The control board will re-detect the open or short circuit condition on the next startup or monitoring cycle and trigger the blink pattern again. Clearing the code without repairing the sensor is not a long-term solution.

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