|
Look *very* carefully at the diagram. It says "Ground (Blue Relay Module) OR +12VDC (Red Relay Module)" (emphasis added) What they meant was exactly what you suggested. You hook both devices up to ground, not one up to ground and one up to +12V (providing you have a Blue module. Otherwise hook up both to +12V.) In no case should you hook up one to Gnd and one to +12 for the reasons you mentioned. They probably could have come up with a clearer way of presenting this.
Also, for the Red Spike where you are hooking both up to +12V, nothing says that this is supposed to be the unfused terminal block. I'm sure that FIRST meant for you to hook to the fuses, not straight to the battery, they just didn't present the idea too clearly...
__________________
/* Daniel */
|