Replacing a C5 plug

[Studude]

I have an AquaSurge Pro 2000-4000 pump by AquaScape. The pump is about 8 years old and is in good condition. The cord from the pump has C5 connector which plugs into a control box for a remote to control on/off and volume from 2000 to 4000 GPH. The control box also has a manual on/off switch. The control box has a C6 connector to accept the C5 plug and then a standard NEMA 5/15P plug to connect to the outlet. The remote never worked well and we haven't used it and don't need it. The manual switch on the control box is now broken. I don't think it is feasible to replace just the switch and a replacement control box is over $100 and has an average 2 star rating - same experience as we had with our remote. So after all that... my question is whether it is feasible to make a safe connection without using a control box at all. Because the C5 is a female connector, there is no adapter that goes male to male, C6 to NEMA 5-15P. Of course I could just cut off the C5 and wire on a NEMA 5-15P since they are both 3 prong 110 A/C, but I am nervous about doing that without fully understanding the possible ramifications (such as killing my pump). Anyone know if it is feasible to direct wire without a controller or am I stuck buying an expensive crappy new controller?