I have a ace 1/3 hp sump pump it will not come on, what could be the problem

sounds like a jammed impeller or blocked intake screen.

There should be two wires that go to the float switch. Jump the 2 pins that are connected to those 2 wires.

www.ereplacementparts.com is the most complete place I have found

Do you mean it won't pump last inch of water or so? sump pumps are not designed to pump completely dry. vane pumps will pump dry. If you are pumping from one tank to another and after pumping is complete, and fluids transfer back, install a check valve on output hose to prevent back-siphoning , or don't submerge output hose on other tank. Hope this helps.

The switch has failed. Replace it with a new mercury type rated to handle the pump.

these pumps are supposed to be sealed and not to be able to oil,,

I found a replacement switch which is placed in series with the pump power plug. However when I removed the original switch and plunged the new switch I discovered that the pump motor spins but it does not pump. I installed a new pump.

Thanks!

I have been in this business for a ong time 34 years by the time ou take the pump apart and find the right peices it would be cheaper to buy a new pump, suggest zoeller submersable pump,,

the drive shaft is broke that why it is easy to turn, the pump needs to be replaced

The higher you pump the water, the stronger your pump needs to be, or the skinnier your hose needs to be. A lower discharge point and / or a smaller diameter hose might help immensely.