Ron,
You are on the right tract and thanks for hanging in there. Once you figure it out, joy will be your reward!. Normally relay 5 and 6 only activate when they see 12volt from the t-stat. If a 12volt source is accidently powering up the black wire, you get the blowers. With the t-stat connected but turned off, the black wire should not have 12 volt.
I would definitely install the Coleman t-stat once you solve your issue. It has a digital read out of room temperature and set points and works well with the Hurricane furnace/water heater. Another feature is if left on "auto" and it calls for cooling, it only turns on compressor #1 to try and maintain ambient temperature to save power. If not satisfied, it turns on compressor #2 also to satisfy your set point. Blessings, Fred