One, no manual for Classic ECD40E made by Woods. Two, recieved from a friend, someone tried to fix, need wiring diagram to make sure wires are in correct postion. Reason: Compressor turns on for a few minutes then shuts off. Stat set on max and fan on high. Wondering if neutral and hot wires changed on relay on compressor?

SOURCE: Whirlpool 50 pint dehumidifier

the problem just might be that your are trying to use this unit at a time of season that is cold weather. there is no humidity in the air so the unit is cycling on and off .there by the noise you hear. dehums work best when the temp is 65 degrees or higher and the humidity level is 60% or higher. and that means outside. in order to have humidity the water has to be heated up to the point that it starts to evaporate.

SOURCE: DH30 Dehumidifier Compressor Does not Operate

I just picked one up at a tag sale, seller said it worked sometimes. Seems to have the same problem as yours. I took the time to tweak all of the connections and then re-soldered the control board with no luck. I finally disconnected the humidity control and it worked fine. By disconnecting the humidity control the unit defaults to it's highest setting and you have to unplug the unit to turn it off. Conclusion so far is that the humidity control rheostat is bad.
Note: Now while running the fan runs continuously and the compressor cycles on and off every 10 to 15 minutes. This may to be normal since the unit appears to be doing its job and I'm not sure how it is supposed to run since a purchased it broken.

SOURCE: compressor runs, overheats and shuts down..fan does not run...

I have had the same problem. Following the advice of someone on these pages I opened the machine up and checked the fan with a meter. On my model (the 404) it has two settings so two leads; one seemed okay, the other was dead. I checked the circuit where the fan connector plugs in and I got that both speed settings were supplying plenty of juice. Apparently the fan motor is dead. A replacement runs $79 at http://www.appliancefactoryparts.com/. I ordered one; we'll see what happens.

SOURCE: Fan runs, all controls work compressor does not run.

It sounds as if the unit has lost it's refrigerant charge. Take to small appliance repair for confirmation, but it probably leaked out.

SOURCE: Humidifier compressor does not stay on more than 1-2 minutes

Sounds like bad relay on compressor or bad compressor. There is only so far you can go yourself without knowledge in electrical and AC units. Suggest you call a service tech or if you can take it to service cemter near you. Russ