Craftsman 3 Gal. Air Compressor 1 HP Hortiz

The manual for the compressor will tell you how. If you do not have the manual try here:

Craftsman 16639 1 HP 7 Gal Portable Air Compressor Manuals

after scewing the fittings on hose & compressor with thead tape (ofcourse) ,simply pull the collar back on the female fitting & incert the male fitting & release the collar .----------these may be called quick connectors but they require a little effert under air pressure.

If it makes hesitation sounds just before shutting off, you need to oil the compressor as per the manual. This is the most common problem.
If it is kicking on and off normally, you need to adjust the pressure relay. The instructions are under the cover.

Check for a leak between you compressor head (pump) and your tank. Your pump output may be good but as your tank pressure gets higher the leak will not allow the tank to build up.

Hi, Larry, W/D here.
Locate where the electrical cord goes to the compressor (a gray or black box). That is your pressure switch, and has a lever next to it, usually with a red rubber tip on it. Flipping the lever turns it on. To hook up the hose, locate the female hose connection at the regulator. It is either the type where you slide the collar back and insert the air line, or the type where the collar is already back, and locks into place when the hose is pushed in.
The regulator on this model is adjustable; the gauges are separated by a knob between them. The knob allows you to adjust the output pressure. The inner gauge, closest to the compressor, shows the pressure on the tank, and the one closest to where tha hose takes off is the "working" pressure. Don't adjust the pressure unless there's a need to. Between the gauges is a small cylindrical brass piece with a ring in the top of it. This is the pressure relief device. It will open if the compressor fails to shut off when it is supposed to. You don't need to do anything to that either.
If the compressor runs a bit, it will produce moisture from the heat of compression, and the moisture will collect in the tank. It is a good idea to drain the tank down from time-to-time to keep the moisture from rusting out the tank. there is a small valve on the underside of the tank for this purpose. When you know that you are going to use the compressor a lot, you can crack the valve, just a bit, to keep the moisture drained.
This should get you started.
Best regards, --W/D-- Please feel free to rate this solution, and let me know if I can help further.

When a compressor reaches set pressure, there should be a release of air from discharge hose thru the unloader. This release of air unloads the compressor head pressure. The unloader is usually located within the pressure switch. Easy to check. Follow discharge hose from compressor head to tank. There should be a brass/steel checkvalve at the tank. The checkvalve allows air to enter tank, however not allow air to be released back into discharge hose. If this valve is leaking, air will be released from the unloader constantly. Follow 1/4" tubing from checkvalve to unloader and listen for leaks. Repair as needed. If air is not leaking from checkvalve then check unloader mechanism with-in pressure switch. Parts are available at www.toolpartsdirect.com Good luck

Cold weather will freeze the water the compressor normally makes and this can prevent the switch diaphragm from releasing.... also drain the tank

Its best to use a 30wt non detergant

put a blower on the hose and see if air comes out
very possible there is a blockage in the hose or if you are using quick connects they may have failed