Turn Signal Parts at Easy Life Markets
Turn signal parts are the switches, flasher relays, bulbs, sockets, lamps and wiring that make your indicators flash. Easy Life Markets sells turn signal parts as part of our car lighting section, inside the wider auto parts store. If your indicators work on one side only, flash too fast, stay on or do not cancel, the fault is almost always in one of these parts.
Our current range is one part: a Chevrolet GMC turn signal switch for 1967 to 1972 Chevrolet C10, C20, C30, K10 and K20 pickups and the matching GMC C and K series trucks. It comes as a complete assembly with the switch body, a colour-coded ribbon of wires and the long flat plug, and the supplier lists it as SWA41605 with interchange number TW-24. We will add more over time. This guide explains how an indicator system works, the parts in it, how to find a fault and what to check before you order. The current price and availability are shown on the product page.
How a Turn Signal System Works
When you move the indicator stalk, the turn signal switch connects power to the lamps on one side of the vehicle. A flasher, either a separate relay or a function inside a body control module, switches that power on and off so the lamps blink. A small indicator on the dashboard flashes at the same time, and on many vehicles you hear a clicking sound.
When you straighten the steering wheel after a turn, a cancelling cam on the steering column pushes the switch back to the centre. The hazard switch flashes all the indicators at once, usually through the same flasher.
On older vehicles, the flasher measures the current through the bulbs. If one bulb fails, the current drops and the flasher speeds up or stops flashing. That is the car telling you a bulb is out. Modern vehicles often do the same thing electronically. The automotive lighting article on Wikipedia covers indicator lamps along with other vehicle lights.
Main Types of Turn Signal Parts
Turn signal switches
The switch is mounted at the top of the steering column, behind the wheel. On older trucks and cars it is a separate switch with its own wiring that runs down inside the column to a plug. On many modern vehicles it is part of a multifunction stalk that also controls the headlights, main beam and sometimes the wipers.
Switches wear out with use. The contacts burn and wear, the plastic gets brittle, and the wires harden and crack where they bend inside the column. The usual signs are a signal that works on one side only, a switch that will not cancel after a turn, a loose or vague feel, or brake lights that stop working on some older vehicles where the brake light circuit passes through the switch. Our 1967 to 1972 Chevrolet GMC switch is made for exactly this job on C and K series trucks.
Flasher relays
The flasher makes the lamps blink. Older vehicles use a thermal flasher, which uses a heated strip of metal to open and close the circuit. Electronic flashers use a circuit and give a steadier rate. LED-compatible flashers are designed to flash at the correct rate with the low current that LED bulbs draw. A failed flasher usually means no flashing at all, or lamps that stay on without blinking.
Indicator bulbs
Indicator bulbs come in many types. Common codes include 1156, 1157, 3156, 3157, 7440, 7443, PY21W, P21W and WY5W. The code sets the base type, the number of filaments and often the colour. Amber bulbs are used behind clear lenses. Clear bulbs are used behind amber lenses. Dual-filament bulbs such as 1157 combine two functions, such as a parking light and an indicator, in one bulb.
Sockets, lamps and lenses
The bulb sits in a socket inside the lamp housing. Sockets corrode, especially on older vehicles and in wet climates, and a corroded socket causes dim or intermittent indicators. Lenses crack and fade. Front indicators, rear indicators, side repeaters and mirror-mounted indicators each have their own housing.
Hazard switches and wiring
The hazard switch can be part of the turn signal switch or a separate button on the dashboard. Indicator wiring runs from the switch to the flasher, then out to each lamp, with a ground at each lamp. A broken wire or poor ground causes the same symptoms as a failed bulb. For looms and connectors, see our wiring harnesses category.
Turn Signal Parts Compared
| Part | What it does | Typical symptoms when it fails | Details to match |
|---|---|---|---|
| Turn signal switch | Selects left or right | One side only, will not cancel, loose feel | Vehicle model and years, column type, plug shape, part number |
| Flasher relay | Makes the lamps blink | No flashing, lamps stay on | Pin layout, number of lamps, LED or standard |
| Bulb | Gives the light | Fast flashing, one lamp out | Bulb code, colour, single or dual filament |
| Socket | Holds and powers the bulb | Dim or intermittent lamp | Bulb base, lamp housing |
| Lamp housing or lens | Directs and colours the light | Cracks, water inside, faded colour | Vehicle model, side, position |
| Wiring and ground | Carries the current | Dim lamps, lamps that glow with others | Wire gauge, connector, ground point |
How to Find a Turn Signal Fault
Most indicator faults can be traced with a few simple checks. Work through them before you buy turn signal parts, so you replace the right one.
- Watch the flash rate. If one side flashes fast and the other is normal, a bulb on the fast side has probably failed, or its socket or ground is bad.
- Walk round the vehicle. Switch on the hazards and check every indicator lamp, including side repeaters and mirror lamps.
- Check the bulb. Look for a broken filament or a blackened glass. Swap it with a known good bulb of the same code.
- Check the socket and ground. Clean any corrosion and make sure the ground wire is tight on clean metal.
- Check the fuse. Your owner's manual shows which fuse protects the indicators. On many vehicles the hazards use a different fuse.
- Test the hazards. If the hazards work but the indicators do not, the fault is often the turn signal switch, its fuse or, on some vehicles, a separate flasher.
- Check the flasher. If nothing flashes at all, with good bulbs and fuses, the flasher is a likely cause.
- Look at the switch. If one side never works, the switch will not cancel or the action feels loose, the switch is worn.
A simple test light or multimeter makes these checks much easier. Our tools and equipment section and the diagnostic equipment category have workshop tools, including the BST100 car battery tester, which checks the battery and charging system. Low voltage can make the flash rate slow and the lamps dim.
How to Match a Turn Signal Switch
Turn signal switches are usually specific to a vehicle family and a range of years. On older vehicles, the steering column type also matters, and switches for tilt and non-tilt columns can differ. Check these points before ordering.
- Make, model and year. Our switch is listed for 1967 to 1972 Chevrolet C10, C20, C30, K10 and K20 and the matching GMC C and K series trucks.
- Part numbers. Compare the number on your old switch, or in a parts catalogue, with the listing. Ours is listed as SWA41605 with interchange TW-24.
- Column type. Check whether your column is the original type for the truck. A column swapped from another vehicle may need a different switch.
- Plug shape and wire count. Compare the flat plug and the wire colours with your old switch and the product photos.
- Wire length. The harness must reach the plug under the dashboard, routed through the column.
If you are unsure, send your vehicle details and part number through our contact page before you order.
LED Indicators and Fast Flashing
Swapping standard indicator bulbs for LEDs is popular, but it often causes hyperflash, where the indicators flash much faster than normal. This happens because the LEDs draw far less current than the original bulbs, and the flasher reads that as a failed bulb. Some vehicles also show a bulb-out warning.
There are two common fixes. One is an LED-compatible flasher relay, where the vehicle uses a separate plug-in flasher. The other is a load resistor wired in parallel with each LED, which draws the missing current. Our H7 LED load resistor shows how this works: it is a 50W, 6 ohm plug-in decoding harness with H7 connectors, which are usually found on headlamps rather than indicators. For indicator bulbs, the resistor or flasher must suit that bulb type. Load resistors get very hot in use, so mount them on metal, away from plastic and wiring.
Fitting Turn Signal Parts
Changing a bulb is a simple job on most vehicles. Changing a flasher is often just a matter of unplugging the old one and plugging in the new one, once you have found it. A turn signal switch is a bigger job, because it sits inside the steering column.
General steps for a column-mounted switch
- Disconnect the battery negative terminal.
- Remove the steering wheel, following the service manual for your vehicle. A steering wheel puller is often needed on older trucks.
- Remove the parts above the switch, such as the cancelling cam and any lock plate, as the manual describes.
- Tie a pull string to the old switch's plug so you can draw the new harness through the column along the same path.
- Unscrew and remove the old switch, then feed the new harness down the column.
- Fit the new switch, reassemble the column and refit the steering wheel straight.
- Reconnect the battery and test both indicators, the hazards, the cancelling action and, where they share the circuit, the brake lights.
The steering column is part of a safety system. On vehicles with an airbag in the steering wheel, special procedures apply, and the work should be done by a qualified mechanic. If you are not confident taking the column apart, have a professional fit the switch. For other column and steering parts, see our suspension and steering section.
Turn Signal Parts on Classic Vehicles
Classic trucks and cars need a little extra thought. On many older vehicles the turn signal switch also carries the brake light circuit, so a worn switch can stop the brake lights working on one or both sides. If you replace the switch, test the brake lights as well as the indicators.
Older systems usually use thermal flashers and standard filament bulbs. They work well when the wiring is sound, but fifty years of heat and vibration take a toll on sockets, grounds and connectors. When restoring a classic, it often pays to replace worn turn signal parts as a set: the switch, the flasher and any corroded sockets. That saves chasing one fault after another. Keep the old switch until the new one is fitted and tested, so you can compare wire colours and plug layout.
Care and Maintenance
- Check every indicator lamp at least once a month by switching on the hazards and walking round the vehicle.
- Replace failed bulbs promptly. On many vehicles a dead bulb makes the remaining lamps on that side flash fast.
- Clean lenses so the amber light is easy to see in daylight.
- Look for water inside lamp housings and replace damaged seals or lenses.
- Treat sockets and connectors on older vehicles with a suitable electrical contact cleaner when you change bulbs.
- Keep a spare indicator bulb of the correct code in the glove box.
Spending a few minutes on these checks keeps your turn signal parts working longer and helps you spot problems early.
Common Mistakes
- Replacing the switch before checking bulbs and grounds. A bad bulb or ground causes many indicator faults.
- Using the wrong bulb code. A single-filament bulb in a dual-filament socket will not work properly.
- Mixing bulb colours. A clear bulb behind a clear lens gives white light where an indicator needs amber. Match the bulb colour to the lens.
- Fitting LEDs without fixing the flash rate. Hyperflash will follow.
- Forcing the harness through the column. Use a pull string and take your time to avoid damaging the wires.
- Refitting the steering wheel off-centre. This affects the cancelling action and the wheel position.
Related Parts and Categories
Our fog lights category includes a fog lamp wiring harness with relay, fuse and switch. If you are fitting extra lamps, the LED light bar wiring harness kit has a 40A relay and 30A fuse. For the rest of the vehicle electrics, see our electrical section and the batteries category.
Who These Turn Signal Parts Suit
These parts suit owners of classic trucks and cars bringing the indicators back to working order, restorers of 1967 to 1972 Chevrolet and GMC pickups, DIY owners chasing a fast-flash or one-side fault, and mechanics who need a specific switch by part number.
Frequently Asked Questions
Why do my indicators flash fast on one side?
A fast flash on one side usually means a failed bulb, a bad socket or a poor ground on that side. It can also happen after fitting LED bulbs.
Why does my turn signal not cancel after a turn?
The cancelling parts inside the switch or on the column are worn or broken, or the steering wheel was refitted off-centre. A worn switch often needs replacing.
Which turn signal parts do you sell?
The category covers switches, flashers, bulbs, sockets and lamps. Our current range is a turn signal switch for 1967 to 1972 Chevrolet and GMC C and K series trucks, and we will add more.
Does the Chevrolet GMC switch come with wiring?
Yes. The listing shows the switch body with a colour-coded ribbon of wires and the flat plug on the end. Check the product page for full details.
Can I fit a turn signal switch myself?
On older trucks without airbags, many owners do, with a steering wheel puller and the service manual. On vehicles with an airbag, have a qualified mechanic do the work.
Do LED indicator bulbs need a resistor?
Often, yes, or an LED-compatible flasher. Without one, many vehicles flash too fast or show a bulb warning.
What if the part does not fit?
See our return and refund policy. Shipping details are on the shipping policy page, and more answers are on our FAQ page.
Buy Turn Signal Parts at Easy Life Markets
Working indicators tell other road users what you plan to do. Check bulbs, sockets and grounds first, match switches and flashers by vehicle and part number, and get professional help for column work on airbag vehicles. Browse our turn signal parts above, or send your vehicle details through our contact page if you need help.