Unfortunately, my abilty to read a schematic is quite limited. But I do have until spring to figure it out. If the mechanic can diagnose it today I'll see what the cost is. He has always been very fair so I expect it will be fine. If he can't get to it today, I'll have to spend more time figuring it out. Always good to have a challenging project to keep you on your toes. He is definitely checking the pressure which is good since I don't have the gauges. A good voltmeter is not too expensive so I can get one and learn to use it which would be a good skill to acquire. Fix a problem and get an education to boot. Not a bad deal.
If I need to diagnose it myself, I'm sure I'll have more questions in the future. As always, I thank you all for your invaluable input. If not for this site, I maight well not have felt comfortable enough to buy this car.