How to Wire Mosfet Power Module to RAMPS 1.4 Board

[printbus]

Welcome to 3DPrintBoard.

The bed heating failed error was probably a problem with the temperature sensor on the bed, or the wiring to it either being open or shorted.

I don't have first-hand knowledge with that module, but it sounds pretty typical. First, make sure the 11-amp input on RAMPS has 12V going to it. No, you're not going to use it to power the heat bed, but the RAMPS D8 Mosfet needs to have that 12V there for it to work. Then, connect RAMPS D8 to the control input on your module. Connect heavy gauge wiring from your power supply to the DC POWER connections on the module. EDIT: And yes, you do need two 12V connections from the power supply to RAMPS, and an additional 12V connection for the module. There's very little current going through the D8 circuit when you're using an external relay or switch module like this, so the 11-amp input can actually be powered by lightweight jumpers to the RAMPS 5-amp terminals if you wish.