Daewoo Lanos 1999-2002 Relay Guide: Solving Common Electrical Faults
If your Lanos cranks but won't start or stalls unexpectedly, a simple, inexpensive relay could be the culprit.
- A bad relay is a common cause for a Daewoo Lanos that cranks but won't start or stalls intermittently.
- Before replacing a relay, check for the known wiring harness issue under the passenger-side carpet, as it causes similar symptoms.
- Use the 'swap test' by exchanging the suspect relay with an identical one from a non-essential system (like the horn) to diagnose the problem for free.
- Replacing a relay is an easy, tool-free DIY job that can be done in minutes.
Is a Bad Relay Causing Your Daewoo Lanos Problems?
The Daewoo Lanos is a straightforward car, but like any vehicle, it can develop electrical issues over time. Relays are common failure points that can cause frustrating, often intermittent, problems. Because they are simple switches, they can fail completely, work only some of the time, or get stuck in the 'on' position. Understanding the signs of a bad relay can save you from more expensive and unnecessary repairs.
Known Issue: Check Your Wiring First
A recall was issued for some Lanos models due to a wiring harness located under the front passenger's carpet. This harness can rub against a body seam and become damaged, leading to sudden engine stalling. These symptoms are nearly identical to a failing main or fuel pump relay. Before replacing parts, check this wiring area for any visible damage.
🎬 Watch this video to see how to troubleshoot Lanos wiring issues.Symptoms of a Failing Relay
The symptoms depend entirely on which relay is failing. The most critical and common failures are related to the main and fuel pump relays.
- Engine Cranks But Won't Start: This is the most common sign of a bad main or fuel pump relay. The starter will turn the engine over, but the engine won't get the fuel or spark it needs to run.
- Engine Stalls Suddenly: The engine may start and run for a few seconds or minutes before shutting off unexpectedly. This can be intermittent, making it hard to diagnose.
- No 'Click' Sound: When you turn the key to the 'On' position, you should hear a faint click from the fuse box as the main and fuel pump relays activate. If you don't hear this, the relay may be dead.
- Component Not Working: A simpler symptom is when a specific system fails. If your A/C doesn't blow cold, the horn doesn't work, or the cooling fans don't turn on, the corresponding relay could be the cause.
- Check Engine Light: A failing main relay can trigger the Check Engine Light, as it powers the engine's computer.
Choosing the Right Aftermarket Relay
For a vehicle like the 1999-2002 Daewoo Lanos, finding original OEM parts can be difficult and expensive. Aftermarket parts are the most practical and cost-effective solution.
- Replacement Brand: This brand offers a direct-fit, standard-quality part. For a simple component like a relay, a generic aftermarket part provides a reliable and affordable repair. It is designed to meet the original specifications for fit and function.
Pro Tip: The Swap Test
Your Lanos uses several identical relays for different systems. You can find the relay locations in the fuse boxes under the hood and in the passenger compartment. If you suspect your fuel pump relay is bad, you can swap it with an identical relay from a less critical system, like the horn. If the car starts and the horn stops working, you've found the bad relay.
Estimated Relay Replacement Cost
Replacing a relay is one of the most affordable repairs you can perform. The part itself is inexpensive, and labor is minimal because it is a simple plug-in component.
| Part Type | Estimated Cost |
|---|---|
| New OEM | $35 - $60 (if available) |
| New Aftermarket | $17 - $25 |
| Shop Labor | $20 - $50 |
Frequently Asked Questions
Where are the relays in a 1999-2002 Daewoo Lanos?
The Daewoo Lanos has two main fuse/relay centers. The first is in the engine compartment, typically located near the battery. 🎬 See a walkthrough of the engine bay relay and fuse block. The second is inside the passenger compartment, on the driver's side, often behind a small cover on the side of the dashboard or kick panel. Your owner's manual or the diagram on the fuse box cover will show the specific location for each relay.
What is the difference between the main relay and the fuel pump relay?
The main relay provides power to the Engine Control Unit (ECU) and other essential engine electronics as soon as you turn the key. The fuel pump relay is often controlled by the ECU and specifically powers the fuel pump to deliver gasoline to the engine. While a failure in either can prevent the car from starting, they are two separate components.
Can I replace a relay myself?
Yes, this is a very simple DIY task. Relays are designed to be plugged in and pulled out, similar to a fuse. No special tools are required. Simply locate the correct relay, pull the old one straight out, and push the new one firmly into its place. Always disconnect the battery's negative terminal 🎬 Learn how to properly test a relay using a resistance check. before working on the electrical system.
Why does my car start sometimes but not others?
This is a classic symptom of a failing relay. The internal contacts of the relay can become worn or corroded, leading to an unreliable connection. Heat can also affect a failing relay, causing it to work when cold but fail once the engine bay warms up. An intermittent no-start condition is a strong indicator that a relay is on its way out.
Helpful Videos
Technical Specifications
Varies by function (e.g., Fuel Pump Relay, Main Relay, A/C Relay). Most are 4 or 5-pin standard automotive relays.
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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