New info if anybody's still reading this:
I recalled that when I first went to hook it up after thinking it would work with the new heavier gauge wire, it sparked and popped when I connected the negative cable to the house battery. I opened the Ctek and found the one of the blade fuses on the circuit board was blown. I replaced it and hooked it up again to test. Same thing happened when I connected the negative to the house battery. I replaced it again and very carefully went through the connections. With the negative disconnected form the starter battery, I connected all the positive wires, then the negative to the house battery, then the negative to the starter battery. It popped again, this time blowing the fuse between the Ctek and the house battery positive. All fuses are 30 amp. Am is missing something other than a bad ground, even though I am grounding both the ctek and the house battery to the accessory stud on the negative terminal/ground cable of the starter battery?