The ignition switch or key switch on ATVs is prone to fail over time due to internal corrosion or mechanical failure from extended use. If you suspect your ignition switch is not working, you should test it before spending money on a new unit.
This post covers the following topics:
- How an ATV ignition switch works
- How to troubleshoot and test an ATV ignition switch.
- How to replace an ATV ignition switch.
How Does an ATV Ignition Switch Work?
ATV ignition switches come in many designs and layouts. Some are simply ON and OFF, while others serve multiple purposes and have multiple settings or modes, depending on the make and model of the ATV.
The most common modes are:
- STOP or OFF: Break all electrical power from the battery to the vehicle.
- ON: Activates the electrical power to the vehicle. ATVs with a separate start button will only start when the ignition switch is in this mode.
- START: Activates the starter to start the engine. This applies only to ATVs that use the ignition switch to start the ATV and do not use a separate starter button.
- Different light modes. Toggle between the modes when the ATV is running.
- LIGHTS ON. Turns the headlights and taillights on.
- PARKING LIGHTS ON: Turns the parking lights and taillights on.
This is what a typical ATV starting circuit may look like. Note that your ATV might be wired slightly differently, but many of the same basic principles apply.
How to Troubleshoot and Test an ATV Ignition Switch?
If you suspect your ignition switch has gone bad, here is how to troubleshoot and check if it works.
1. Ensure the Battery Is Charged and Properly Connected
Checking the quick and simple things first is always a good idea.
2. Check for Blown Fuses
The ignition switch is usually fused, and often several ways. Locate the fuse box and check all the relevant fuses. Also, ensure the main fuse is not blown.
3. Check if the Instrument Panel Turns On
Most of the time, if the instrument panel turns on when you turn the ignition switch in the ON position, you know the switch is good.
However, in some cases, only the starter button circuit fails, so the ATV cannot start even if the instruments light up.
4. Check for Damaged Wiring
Often you will find that the switch is OK, but it does not work due to faulty wiring or bad connections.
Look for signs of previous repairs that might not have been performed correctly.
5. Test the Ignition Switch Using a Multimeter
To test if your ignition switch works properly, you’ll need a multimeter to test the switch for continuity.
Your testing aims to ensure the electric current is directed correctly in each key position and there are no shorts or other disturbances inside the switch due to mechanical failures or corrosion.
Multimeter settings to test for continuity:
- Connect the black test lead to the COM port.
- Connect the red test lead to the V (voltage) port.
- Turn the multimeter dial to the continuity setting, symbolized by a diode (triangle with a line on the right side) or a sound wave symbol, referring to the continuity test sound.
- Put the test leads together to ensure the multimeter works. When there is continuity (a good connection), the multimeter should sound an audible beep or buzzing sound, and the display will change from 1 to 0.
- To test for continuity, put one probe on each connector; the order does not matter.
The testing order varies depending on the switch layout, but the basic principles remain the same. Here is the testing order of a basic ON/OFF ATV ignition switch
- When the switch is OFF, there should be continuity between the Green ground wire and the Black/White CDI wire.
- When the switch is ON, there should be continuity between the Red battery wire and the Black starter button wire.
The testing order on more advanced switches varies, so unfortunately, no universal testing procedure will work on all switches.
One option is to go by logic depending on each wire goes. For instance, the ACC wire powering the lights and instrument panel should have continuity to the battery wire when the switch is ON, and so forth.
A better alternative is to get your hands on a vehicle-specific service manual showing the exact testing order.
The below diagram shows the testing order to test the ignition switch on a Polaris Sportsman (international model).
How to Fix an ATV Ignition Switch?
Generally, it is not recommended to repair a failing ignition switch as the results will likely not last long. A new ignition switch is relatively affordable, and replacing the switch is considered a better alternative in the long run.
However, in a pinch, you might be able to get the switch working again with proper cleaning.
This only works if the switch is dirty or corroded and not when there is a mechanical failure like a broken pin connector.
How to Clean an ATV Ignition Switch?
Things you will need:
- An air compressor with an air spray nozzle.
- A small flathead screwdriver or a pick.
- Universal ruist remover
- Paper towel
This simple cleaning procedure might remove internal corrosion that prevents the switch from working.
- Use compressed air to remove any debris off the key.
- Spray some rust remover on a rag and wipe off the key.
- Use a pick to keep the ignition switch key slot latch open and direct the air nozzle into the slot to blow out as much dirt as possible.
- Spray a generous amount of rust remover into the switch through the key slot.
- Turn the key on and off several times.
- Repeat spraying and toggling the switch a few times until it starts working.
If that doesn’t work, you need to find a way to disassemble the switch housing. Most of the time, the switch housing is not designed to be disassembled easily, but this varies.
After opening the switch housing without damaging the internals, use a small flathead screwdriver to scrape off any corrosion. Also, check for loose connections or other signs of damage.
If cleaning the switch does not work, there are ways to bypass the ignition switch altogether. However, I’m not in the business of educating potential ATV thieves, so unfortunately, I won’t be sharing how to hotwire an ATV.
How to Replace an ATV Ignition Switch?
Replacing an old ignition switch with an identical new one is relatively straightforward.
- Disconnect the negative battery terminal.
- Access the backside of the switch. On some ATVs, you need to remove a plastic cover; on others, you need to release the switch assembly retaining nut and pull it to the front.
- Take photos of the old switch backside to know where each wire goes.
- Disconnect all wire connectors and remove the switch.
- Install the new switch by performing the above steps in reverse order.
But what if your new switch is slightly different, or your old switch was missing, and you don’t know how to wire the new switch?
I’m afraid the specific wiring varies between different brands and models of ATVs, but this is what a typical ignition switch wiring looks like.
What Are the Signs of a Faulty ATV Ignition Switch
Besides testing the switch with a multimeter, how do you know if your ATV ignition switch needs to be replaced?
Some of the most common signs of a faulty ignition switch or a switch that is beginning to go bad include the following:
- ATV is not getting any power.
- Intermittent starting problems.
- The instrument panel turns on, but the starter button does not activate.
How Much Does It Cost to Replace an ATV Ignition Switch?
A new ignition switch typically costs 15$ to 20$, and a mechanic would use about 30 minutes to 1 hour to replace it. This gives us an estimated replacement cost for an ATV ignition switch of $30 to $60, including parts and labor.
If you replace the switch yourself, you’ll only have to pay for the switch and basic electrical supplies.
NOTE: Some ATVs may have more advanced features like electric theft protection built into the switch. If you’re unsure whether the switch on your ATV is plug-and-play or may require specialist tools, I recommend talking with the dealer in advance.