Why is this good news? Because if he hadn't I would have paid him the $80 we agreed to and not been happy with the result. I had asked at first if we could run a switch under the dash to cut off the battery. He said he couldn't do that, but he could put a switch on the battery. He quoted me two prices, one for a cheap switch, another for a good switch. I chose the good switch and was there this morning for an 8 o'clock appointment. But before I showed up for that appointment I went to the local parts place and asked to see what switches they had. They had a much cheaper cheap switch ($12) than the mechanic had quoted me and a ($50) switch with two terminals and no mounting brackets. So when the mechanic showed me the exact same $50 switch and tried to rip me off by saying it would be $100 instead of $80, I was prepared. The fact is, I could undo a terminal and connect the switch to hang there not costing me a penny more than the $50 for the switch. It would have been a five minute job. Instead, I'm getting what I wanted in the first place with a switch under the dash. I have an 8:30 appointment tomorrow with a different mechanic that will do the job right and give me what I want.
So instead I have a solenoid on a mounting bracket. I will not have to open the hood to cut off the battery. This makes me happy. Always deal with a mechanic you trust.
Update: Everything was installed this morning and the Jimmy is sitting with the switch off now. Tomorrow morning I will see if disconnecting the battery keeps it from draining and starts my vehicle. I see no reason it shouldn't. My back up plan is a larger solar battery for charging than the little one I have now. That little charger may be useful in charging a second battery not connected to any circuits that could drain it. Before I leave on my odyssey (my personal mars mission) I'll have my brother-in-law help me track down the fuse involved in the drain per CJ's suggestion.