# sears craftsman air compressor



## frenchelectrican (Apr 12, 2006)

Most likely the starting switch is hung up that is kinda common cuprit however some case you will have bad starting capaitor as well if your motor do have running capaitor it will trip the breaker or stall the motor one of the two.

I just got back from service call one of my customer have starting switch got hung up due very fine saw dust got the starting switch stuck in run postion so clean it out and relube it and it run smooth now.

Merci,Marc


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## micromind (Mar 9, 2008)

Is there pressure in the tank when it won't start. If it'll start with no pressure, but not with pressure, then the unloader valve is bad. 

Can the pump be turned by hand? It should turn easily, even with pressure in the tank.

If it turns easily, but still won't start, then it's almost certainly either the start switch, or the start capacitor. 

If a replacement kit is made, it'll most likely solve the problem.

Rob


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## frenchelectrican (Apr 12, 2006)

Rob.,

Thank for bring it up the unloader valve that is the other item you need to look at it when the compressor go off you should hear the unloader valve kick open.

For common resdential and light duy commercal compressors the unloader valve will be on the pressure switch itself you will see either quarter inch or 3/8 inch tubing to the pressure switch that is the unloader valve.

my large compressor the unloader valves are in the head itself due I have dual mode set up on my compressor.

Merci,Marc


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## blacktrain (Mar 27, 2010)

there is no pressure in the tank and the pump turns easy, the motor hums when you plug it in. Thanks again for your help...


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## frenchelectrican (Apr 12, 2006)

Now I am more leaning either starting switch malfuctioned or bad starting capaitour.

However let me give you a stern warning with capaitour even thru you disconnect the power the capaitour will hold the charge for a bit while and if you are not carefull it can nail ya.

So some capaitour do have restitour to bleed it down or you have to manual short it out with screwdriver.

To get new capaitour you get the same or higher voltage rating and the size it should be the same or little larger but NEVER smaller.

If the switch is good and capaitour is good then you have bad starting winding.

Merci,Marc


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## stingray944 (Jun 23, 2010)

*K-0645 availability*

Hi, I'm new to the forum. I can't find the part k-0645 for my air compressor. Sears parts direct is out and it is no longer available. Any ideasw where I could get the starting capacitors? Thanks.


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## behrend (Jun 11, 2010)

I bought a new starting capacitor for my compressor from Digikey. Just make sure it is the same capacitance (or slightly higher) and the same voltage (or slightly higher). Be sure to pick an AC capacitor. You can also measure the can size of the old start cap to be sure your new can size will fit. Also, if they use any type of faston connectors, be sure these are tight and making a good connection. This was my issue, not a bad cap.


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## frenchelectrican (Apr 12, 2006)

Most electric motor shop will have a capiatour on hand or can order one real quick depending on the size of capaitours.

And few large HVAC or Electrical supply centres may have them as well { not all will stock it }

Merci.
Marc


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