I've had ground cable ends get loose and break off in the past. Always better to be safe than sorry
kinda like having two batteries in your boat...it just make sense!
Yeah for sure, I guess I'm looking at this from a warranty point of view. If it's set up as per instructions, and it's faulty, well, they should replace it.
So, here's something...I have been playing around with this brain that I had here (brand new) that would only spark on the brown channel. I recieved an RMA number from MSD and thought I would test it one more time before I sent it off so I wasn't charged a fortune to have a look at an ignition that was perfectly fine. Shorted the brown wires, spark, shorted the yellow wires, spark...This seemed a bit strange as I had tried this previously and it didn't work. I removed the ignition plate, flipped it over, and found the orange channel was plugged into the coil (from previous testing). So, it turns out that all three channels are fine, but the orange and yellow wires must have been installed incorrectly inside the brain. So, to the OP, determine which wire produces spark, and leave that one alone. Then, plug in one of the other channel wires to the coil (eg yellow, or orange) and short across all three pickup wires leading into the brain. If the wires are switched somewhere internally, you should get spark. So, you have the brown channel plugged into the coil, it sparks. Plug the yellow channel into the other coil, and short across the orange wires entering the brain. If it sparks the coil, yours will be switched like mine. Plugging the orange channel in and shorting across the yellow wires should then also produce spark on that same coil.