Bruce, How they work: Turn on the key and immediately you have 6 volts. Hit the starter and you get 6 volts to the nominally 4.5 volt coil. (less whatever cranking load does?) Anyhow that gets you started with good voltage. With a Chev driver, two minutes in, with the key on and the michrome? wire is red hot( thats why its in a cage, to stop him/ she, it, +etc. burning (gender neutral self) and it is down to 4.5 volts. Now try and start it and the cranking load drops (further) the voltage to the coil to 3.5 volts (my example) and the bloody thing wont start. Now the Chev fan hops out and mumbles under his breath about bloody Fords. The actual fault is him and his lack of knowledge / procedure.
I would think your new unit had some preservative / contaminant on it. You have cleaned it. Now just wait for (quoting Rob) it to heal its self.