Why Does My Air Compressor Keep Shutting Off? Solutions & Causes

Published Categorized as Air Compressor Won't Keep Running 20 Comments on Why Does My Air Compressor Keep Shutting Off? Solutions & Causes

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by Jon dee

Compressor shuts off without reaching full operating pressure (circuit breaker trips)



Make sure the power supply to your Harbor Freight air compressor is “clean”. By that, I mean no extension cord is used, and no other appliances pulling power from the same circuit the air compressor is on.

If the problem persists when you have clean power, then it might be a failing pressure switch allowing a short and popping the breaker, it could be the motor is laboring and pulling too many amps, it could be the start/run capacitor isn’t working right… many things.

What pressure does it reach before the breaker pops, and is the breaker popping at the same pressure on the compressor every time?

Post a response here please, if you wish, so I can follow the thread.

by: Jon dee

Pressing the reset button after the circuit breaker trips allows the compressor to reach full pressure. it runs about one minute before it cuts off each time.

Hoping that you have clean power, as noted, at what pressure does the breaker trip? Same pressure each time? If it’s happening at differing pressure points, then it may not the pressure switch.

Reset switch
by: Anonymous

OMG fellas. don’t make a huge project out of this. by-pass the reset switch. That’s all that’s wrong. Just cut the wires, twist them together and spin a yellow wire nut on there.

That’s one line of thought. On the other hand, if the reset is tripping due to overheating of the motor, then by following your advice you will, for sure, overheat the motor. Not good if you want your motor to last.

Compressor always needs resetting
by harry

Hi, what up. I have had my compressor for about 2 yrs. The same one you have. From day one I have to hit the reset 10-16 times before it will stay running. First I used an extension cord so I did away with that. Now it is directly into an outlet. It still does it and I have tried different outlets with the same results. I do not use that much!

It is so loud it hurts your ears. Next it is full of air 150 psi. Shuts off and go to check the air in my tire and I put in 5lbs.and the compressor kick back on and it keeps doing that so anything I am working on on and off on and off.

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I have this fortress air compressor that will stop before reaching full pressure and it won’t turn back on in till I have turned the switch back off and waited a couple of minutes. Then I can turn It back on and it will build some more pressure until it kicks off again. I have checked the capacitor with a multimeter, and the previous owner has replaced the pressure switch. What should I do next?


Compressor fills to 90 psi the shuts off but the motor continues to get super hot

Is it on an extension cord?
Normal cut-out is what? 125psi?

So I have a 20 gal Kobalt vertical compressor. Single stage oil-less 120V. The compressor will run for a minute or two and fill to about 50-75psi and then shut off. It will not turn itself back on unless you unplug it/flip the switch to off for a min or two and try again. It will then fill to about 100psi and do the same thing over and over. Subsequent cycles seem to be shorter but haven’t timed it. It isn’t tripping a breaker, the motor doesn’t feel warm at all, I’ve tried isolating the circuit, all to no improvement.… Read more »

Got an actual model number?
How does it stop? Sort of a grind to a stop, or more like you unplugged it?
Clarify: does it take a couple minute delay for it to run again regardless of using the switch or unplugging it?

Model number is at the top of that screenshot.

It stops as if you unplugged it.

For your clarification: it takes a few minutes regardless of how you turn it off. The delay begins from when the switch is turned off or it is unplugged so I don’t think it’s an overheating issue.

OK. Next thing is check the capacitors.
Here’s how, if you need it –


Let us know what you find.

I have a Husky 26 gallon “Verizontal” compressor. It shuts off at about 40-50 lbs of pressure every time. Electrical outlet/breaker are fine and do not trip. Turning to increase the pressure valve doesnt help. Any ideas? Thanks.

“Turning to increase the pressure valve doesnt help.”
That’s correct. That has nothing to do with it shutting off.

Model #WL650703AJ Husky “Vertizontal” 26 gallon

OK, so if you let it sit, and maybe unplug and plug back in after a minute or two, do it start (or try to)?
If not, then check if there is voltage across the motor.
Those checks should tell us if this is a motor problem or a bad pressure switch.

I’ve done that. It starts fine…just shuts off after about 5 minutes and 50lbs of pressure.
Shouldn’t that be a pressure switch issue? How much do those cost and are they easy enough to change out? I had some guys quote me almost $300 over the phone, which is ridiculous.
Thanks for your help.

I’ve done that. It starts fine…just shuts off after about 5 minutes and 50lbs of pressure. …and the voltage across the motor was? Shouldn’t that be a pressure switch issue? …possibly, that’s what my previous post was about. How much do those cost …$40-60, depending on source and are they easy enough to change out? …depends on how good you are at plumbing. If you have the right tools, probably an hour or so job. If not, maybe a day or a week or never. … I had some guys quote me almost $300 over the phone, which is ridiculous.… Read more »

I had a problem where my 21 gallon HF compressor would only run about 30 sec. before tripping the on-board breaker never going above 50 PSI. I had replaced the original oil and put in the correct amount of new oil. It look like it was just to the fill line, but apparently, its difficult to get all of the old oil out and the fill line is not very accurate to the eyeball. I solved this problem by draining about 2 ounces of oil from the case. On the next start it went directly to 125 PSI.

Thanks for this. You do need to have the *pump* level to get a useful reading from the sight glass. Not always easy on an upright.

I have a 4.5hp 21 gallon cen.pnue. air compressor and it wont build up past 40-50 psi. And as im using whats in the tank, it does not kick back on to refill itsself.

So John –
What happens when it reaches 40-50 psi if you do nothing?
And does the pressure hold?

It shuts off. And yes it holds the pressure in the tank. But when i use and accessory like a blower nozzle. The pressure aint what you would expect.

That sounds like it’s tripping the motor breaker. You press the motor reset button and/or toggle on-off to get it going again? You may have a bad run capacitor. I’d check that, if I weren’t running it on an extension cord. Scroll down to the search box and enter “testing capacitors” if you don’t already know how. An aside: The specs for Model 47065 motor say “3 H P W o r k i n g / 1 2 0 V o l t / 6 0 H z S i n g l e P h a s e… Read more »

Yes i have to push the reset button to get goin again. But thanks for the info i will try that.