Harley Davidson Won’t Start? (Solved & Explained)

Whether on a road trip, on your way to work, or just out in the neighborhood cruising, getting stranded with a Haley Davidson that won’t start is more than just inconvenient; it’s a buzzkill.

These days, well-maintained and responsibly owned Harley’s aren’t known for starting problems any more than any of the other modern moto models.

That said, here are some of the most common reasons a Harley Davidson motorcycle won’t start.

Here’s Why your Harley Davidson Won’t Start:

The most common reasons a modern, fuel-injected Harley Davidson won’t start are dead or expired bike or key fob batteries, faulty wire connections, or a bad fuel pump. On older Harleys, clogged carburetors and fuel tank reserve switches that have been accidentally switched off are common culprits.

Harley Won’t Start

Listed below are the most common culprits as to why a Harley won’t start.

Dead Battery

A dead battery is the most common reason why a Harley won’t start (or any motorcycle for that matter), and it usually occurs when the battery hasn’t been used for a while or it can be caused by parasitic drain; thus, the battery loses its ability to power the bike.

Parasitic drain is when the bike’s electrical system continues to draw power from the battery even when it is switched off, it’s often caused by poorly grounded wires or short circuits.

If the battery is completely drained your Harley won’t make any noise when you start it.

If you’ve still got some life left in the battery you might be able to turn the key as well as turning on your blinker, although turning it over will feel very slow and sluggish.

Solution: 

  1. Take a multimeter
  2. Set it to DC Voltage
  3. Use the 20 volt setting of direct current
  4. Put the leads on the two battery terminals
  5. If you see a negative number, you need to connect the leads to the opposite battery terminals

If the multimeter shows a reading just under 12V you should be able to just charge the battery and start up your Harley.

However, if the multimeter displays anything lower than 9V you will most likely need to replace the battery.

If your battery troubles continue and you’re still losing voltage, you can always try using a battery tender – this will charge the battery only when it needs to be charged and when you’re not using it.

Kill Switch Set to OFF

You’d be surprised how often even expert-level riders accidentally flick their rocker switch into the OFF position while getting in the saddle.

Your Harley’s Kill Switch needs to be set to the RUN position for the bike to start.

Petcock

There are still plenty of Carburated Harley’s on the street these days, making this item at least worth mentioning.

Carbed HD bikes had a fuel valve or petcock switch that allowed riders to switch between the primary fuel tank and a reserve fuel tank.

Most Harley petcocks also allowed riders to shut the fuel flow off together for servicing and storage, etc.

If your Harley-Davidson’s petcock is turned to the off position or to the ON position while there’s only fuel in the reserve tank, your Harley Davidson motorcycle won’t start.

Side Stand Extended

Modern Harley-Davidsons also have a side stand safety switch that overrides the motorcycle’s ignition system while the kickstand is down unless the bike is in neutral.

Furthermore, while the bike will start with the side stand down in neutral, as soon as you put it in gear with the stand still down, the engine dies.

 In some cases, a Harley won’t start simply because the rider forgets to put the side stand up.

In other cases, the side stand sensor gets contaminated or damaged by road debris and thinks the stand is down when it isn’t.

You can try cleaning the dirt, moisture, corrosion, and debris off your side stand sensor, located on the frame near the stand.

If cleaning the debris isn’t enough to get your Harley turning over, the side stand sensor might need to be replaced. 

Harley Won’t Start Just Clicks

A Harley Davidson Motorcycle that clicks but won’t start likely has either a bad battery or faulty component in its starter system. A seized engine will also click and not start up, though this is less common.

Problems with any of the starter’s principal components can stop your bike from starting.

That said, if it’s clicking while trying to fire up, we can isolate the problem to two of the following three main starter parts:

  1. The starter relay is the component that transfers power from the battery to the rest of the starter system. The relay isn’t your problem; a lousy relay won’t transfer enough energy to make a clicking sound.
  2. Your Harley’s starter has a magnetic power transferring component called the solenoid. If the solenoid is bad, the clicking you hear could be the magnet receiving power and failing to activate.
  3. The last starter part is the starter motor. If your Harley’s starter motor is bad, the clicking you’re hearing could be the weak starter motor trying to spin the flywheel to start the engine.

A low-charge or expired battery won’t generate enough power to activate the starter magnet, causing a click at start up that never results in the bike firing up.

Harley Won’t Start in Gear

Harley Davidson motorcycles won’t start in gear unless you pull the clutch lever and disengage the clutch. This safety feature stops motorcycles from jumping forward and dying, which would happen if your HD started in gear with the clutch fully engaged.

Now, if your trust Harley Davidson motorcycle doesn’t start in gear even when the clutch lever is pulled in to deactivate the clutch, check if the kickstand is still down.

As we mentioned in the first section, most modern Harleys have a safety switch that overrides the motorcycle’s starter system if the side stand is down and the bike is in gear.

If the side stand is up and the clutch lever is pulled in, it could be one of the corresponding safety sensors that are not working correctly.

Not only can side stand and clutch sensors get damaged or corroded by riding in harsh conditions but they’re also regulated by the Electronic Computer Unit (ECU), which calls for periodic dealership updates. 

Harley Won’t Crank

If your Harley-Davidson Motorcycle won’t crank at all and there’s no clicking sound, it could be your fuel injector, starter relay, or battery that’s problematic. Otherwise, check that the bike is in neutral and the side stand is lifted.

If the battery is entirely dead or incapable of holding a charge, or if the starter relay is damaged and therefore not transferring power to the rest of the starter system, your Harley won’t start. In fact, it won’t even crank or click at all.

A faulty fuel injector is another common cause of crank failure on a modern HD.

A bad fuel injector will eventually fail altogether, preventing the motorcycle from cranking over no matter how many times you push the starter switch.

That said, you can catch a bad fuel injector early by being aware of the following systems:

  • Rough idling
  • Poor engine performance
  • Dip in Fuel Economy
  • Engine fails to Rev up to the Typical RPM range
  • Pollution/Emissions Increase
  • Tail Pipe Smoke
  • The bike lurks and bucks while throttling
  • Starting problems

Harley Won’t Start In Cold

Like all carburated motorcycles, older Harleys could be challenging to start in the cold weather.

While it’s more common for carbed Harley models to fail to start up when their cold, poorly maintained Electronic Fuel Injected Harleys can also be problematic in cold weather if their spark plugs are worn.

If you are on a newer, fuel-injected Harley, your engine tuning could be running rich, which means its air: fuel ratio is inadequately fuel-heavy.

An increase in fuel flow can increase the rate of spark plug wear that eventually causes your fuel-injected Harley to be just as hard to start in the cold as the old, choke-equipped carburated models.

If an older, carburated HD model is having trouble firing up when it’s cold out, try starting it with the choke out, and be sure to run it on choke while it warms up before you ride it.

Harley Won’t Start After Laying Down

Some Harley’s have a safety switch called a bank-angle or lean-angle sensor. 

The switch senses when the motorcycle is leaning to the point of falling and overrides the motor to avoid the severe injury and destruction a running engine can cause during a collision.

If your Harley falls down, the sensor will override the starter until the bike is stood up and shut off, the key is removed, and the kill switch is flipped off and back on.

There have been some rare cases of Harley’s with sensors that wouldn’t reset after the bike was corrected, even though the bike was powered down and back up and the ECU was rebooted.

If this happens, lift the seat up, disconnect the bike battery terminals, reconnect them and try again.

Disconnecting and reconnecting your Harley battery should force reset the ECU and all your sensors.

Related: How Long Do Harley-Davidsons Last?

Harley Won’t Start After Winter

Although less common on the modern fuel-injected models, there have been consumer reports of Harleys from all eras having problems starting after being stored for winter.

That said, as far as the newer Harleys go, proper winterization and storage preparation per Harley-Davidsons recommendations will avoid all these problems.

Still, the oil tank rests above the sump on some of the older Harleys, especially those in the Softail line.

After a Harley with this design sits for months at a time, the excess oil drains down into the sump, so it looks like the oil pan is emptier than it actually is.

If you filled the bike’s oil before you stored it and the excess oil sits for long enough to drain into the sump, you might assume the oil is low and add more.

Once the overfilled Harley runs for a while, the sump oil will integrate into the oil flow, and the excess oil will be forced out in ways that can make your Harley have trouble starting until the extra oil is drained.

Harley Won’t Start Oil Light On

If your Harley-Davidson motorcycle won’t start, and your oil light is on, start by inspecting your spark plugs.

If they look worn, replace them and see if that starts the bike, shifts the oil light off, or both.

If not, it could be an issue with the pressure or temperature of your oil causing issues.

Or, on certain models, it could be the oil pressure sensor detecting a problem where there isn’t one and overriding the ECU.

Try unhooking your battery terminals and rehooking them to reset your ECU and all your sensors.

If it happens again, your oil’s pressure or temperature could be problematic for real.

Let the bike cool.

You may have to take your Harley in for diagnostics if it keeps happening.

Harley Won’t Start When Hot

If a Harley-Davidson motorcycle doesn’t start while it’s hot, it could be due to a compromise in the electrical system.

As your Harley’s wiring harness gets hot, resistance builds in its circuitry.

So, if your starter’s wires or battery relays or any of the wires associated with starting the bike are slightly frayed, it may start fine when the bike has been sitting, but when it’s hot outside, your Harley won’t start.

It could also be a worn spark plug, bad battery, or a failing slipper spring that grounds out your Harley’s points when it expands due to heat.

Harley Won’t Start After Changing Handlebars

The most likely reason a Harley Davidson motorcycle won’t start after you’ve changed its handlebars is that you pinched or sliced into a wire while you were reassembling or mounting your hand controls.

Start by checking your starter switch and Run/Kill switch wires, inspecting for any pinches or slices in the wiring.

Next, move on to resetting your fob and ECU by disconnecting your Harley’s battery and reconnecting it.

Another common reason this can happen on a Harley Davidsons is that the security feature thinks the handlebars were shifted because the bike was tampered with, vandalized, or someone attempted to steal it.

Resetting your battery will override the anti-theft safety sensors some Harley models come with. 

Harley Won’t Start With Key Fob

Modern Harleys come stock with keyless ignitions that start right up with the press of the ignition switch, as long as the fob associated with the specific HD model is within close proximity.

If the key fob is out of range or your key fob’s battery is low, your Harley Davidson motorcycle won’t start.

In addition, if your fob is in the same pocket as a metal or electronic object, the resulting interference can prevent the bike from starting.

Finally, we suggest you always carry a spare fob battery.

If your Harley Davidson doesn’t start even with the fob present, be sure the fob battery is installed per the owner manual’s instructions.

There should be a label inside your Harley’s key fob dictating which direction the positive and negative battery polarities should be facing when installed correctly; if the fob’s battery is installed incorrectly, the bike won’t start.

Most modern Harley’s have a factory code that can override the safety feature.

Once entered, the bike will fire up whether the fob is present or not.

Since the key fob bypass code is set at the dealership, many used Harley owners weren’t there at the time of programming and weren’t given the reset code from the previous owner.

An experienced HD mechanic once made the rough-estimated claim that only 50% of Harley owners actually know their safe start override codes.

We’re not sure if that number’s close to accurate; we suggest saving your reset code in your phone so a dead watch battery isn’t why your beloved HD motorcycle won’t start.

Harley Won’t Start With New Battery

If you or a mechanic just installed a new battery and now your Harley-Davidson bike won’t start, it’s likely because the battery terminals are loose.

Start by inspecting their tightness, but don’t stop there; even if your terminals are tight, unscrew them and inspect both the terminals and battery for grime.

Another possible reason why a Harley bike with a brand new battery won’t start is due to corroded or contaminated battery ground.

Locate the ground that connects the battery to the engine, disconnect the bolt, and clean it free of grime and corrosion to see if a bad ground is a culprit.  

Harley Won’t Start With Clutch Pulled

All modern Harleys come with a safety feature that stops them from starting in gear unless the clutch lever is pulled in to prevent them from jumping forward when you fire it up.

That said, if you’re disengaging your Harley-Davidson motorcycle clutch by pulling in your clutch lever and the motorcycle still won’t start, it’s due to problematic spark, fuel, or compression systems.

On a Harley that’s incurred wear and tear, either from high mileage, poor ownership, or collision damage, it may be the clutch switch that’s causing the bike not to start.

A worn clutch switch stops a bike like a Harley from firing up when the clutch is engaged–a busted switch might think your clutch is engaged even though you’re pulling on your clutch lever.

I’ve been told you can reset a faulty clutch switch on some Harleys by pumping the clutch lever 12-15 times.

That said, I’ve never tried it. And even if it works, it’s only a matter of time before a failing switch misreads again; replace it asap.

Related: Where Are Harley Davidsons Made?

Harley Won’t Start Lights Flashing

Modern Harley Davidson motorcycles have security systems that will trigger the lights to flash and stop the bike from starting if the key fob isn’t present.

If you do have the fob, it could be the fob battery is weak or dead or installed incorrectly, so the bike’s ECU can’t detect it.