Why Your Generac Generator Starts Then Shuts Off

If your Generac generator starts then shuts off after a few seconds, it’s not just frustrating—it could leave you without power when you need it most. At Best Care Home Services, we’ve helped countless homeowners in the Memphis area get their generators back up and running quickly and safely. In this guide, we’ll walk you through the most common reasons why your generator won’t stay running and what you can do about it—plus when it’s time to call in a pro.

Why Does My Generac Generator Start and Then Shut Off?

When a Generac generator starts but won’t stay running, it’s usually a sign that something’s off—either with fuel delivery, safety sensors, or wiring. Here are the five most common reasons this happens:

1. Low Oil or a Bad Oil Pressure Switch

Generac generators are built to protect themselves. If the oil level is too low—or if the oil pressure sensor thinks it is—the engine will shut down automatically. Sometimes, even when the oil is fine, a faulty sensor can send a false signal that kills the engine.

What to try:

• Check the oil level and top it off if needed.
• If the oil level is good, try disconnecting the oil pressure sensor briefly to see if the generator stays on (just for testing).
• If it keeps running with the sensor disconnected, you’ve likely found the problem.

2. Wiring Problems (Especially Wire 18 or Wire 14)

This one surprises a lot of homeowners: a damaged or grounded wire can send a false “shut down” command to your generator. Wire 18, in particular, is notorious for causing this issue.

What to check:

• Look for corrosion or damaged wires near the control panel or connection points.
• In some cases, applying 12 volts to Wire 14 can keep the generator running long enough to isolate the problem.

3. Fuel Supply Issues

If your generator is running on old fuel, has a clogged fuel filter, or isn’t getting enough gas flow (especially with propane or natural gas), it might start and then die seconds later.

Tips to fix it:

• Replace your fuel filter if it hasn’t been changed in a while.
• If you’re using gasoline, drain out old fuel and replace it with fresh gas.
• Check your gas or propane line for pressure problems or valve blockages.

4. Worn Brushes or a Problem with the Generator Windings

Some Generac models rely on internal windings and brushes to keep voltage flowing after the engine starts. If those are worn or damaged, the engine may shut off because it’s not producing enough voltage to sustain itself.

Solution:

• Check the condition of the brushes and slip rings.
• If voltage output drops right before the engine dies, this could be your issue.

5. A Faulty Control Board

If the generator’s brain—the control board—is acting up, it might not even throw a fault code. But it could still misread signals and shut everything down.

How to know:

• Watch for flashing lights or fault codes on the display panel.
• If nothing shows but the shutdown keeps happening, a bad board could be the culprit.

What You Can Do Right Now If Your Generac Generator Starts Then Shuts Off

Before you call in a technician because your Generac Generator starts then shuts off, here’s a quick checklist you can run through at home:

Step	What to Check
1	Is the oil level good? Test the oil sensor.
2	Inspect wiring (especially Wire 18). Any corrosion or breaks?
3	Is your fuel fresh and flowing properly?
4	Any signs of wear on the brushes or generator components?
5	Any fault codes or display issues on the control board?

If the generator still won’t stay running after these steps, it’s probably time to get professional help.

Why Generators Shut Down Suddenly: What Homeowners Need to Know

Many homeowners assume a generator that starts means it’s working—but when it shuts off within seconds, that’s often a built-in protection feature kicking in. Whether it’s from a fuel issue, safety sensor, or electrical component, the key is finding the source before it causes long-term damage.

When It’s Time to Call Best Care Home Services

If you’re in the Memphis area and your Generac generator still isn’t cooperating, the team at Best Care Home Services is ready to help. Our certified Generac technicians can:

• Run a full diagnostic to pinpoint the exact problem
• Perform on-site repairs for both standby and portable models
• Get your generator running again quickly and safely
• Set up routine maintenance so you’re never caught off guard

We also offer ComfortGuard Maintenance Plans to keep your generator in top shape year-round—no guesswork, no surprises.

Keep Your Generator Ready with Proactive Maintenance

One of the best ways to prevent your generator from starting and stalling is through regular maintenance. Here’s what we recommend:

• Run your generator under load once a month for 10–20 minutes
• Keep oil and filters clean and up to date
• Replace old fuel before it causes clogs
• Schedule a yearly inspection with a certified technician

At Best Care Home Services, we make it easy with affordable service plans and fast response times throughout the Memphis region.

Need Generator Repair in Memphis? Let’s Get It Fixed Today

When your Generac generator starts then shuts off is more than a minor inconvenience—it’s a warning sign. Don’t wait until the next storm or power outage leaves you in the dark. If your Generac generator starts and then shuts off, give Best Care Home Services a call at 901-624-1401 or schedule service online.

We’ll help you troubleshoot fast, fix the issue right the first time, and keep your backup power system ready when you need it most.