Being an electrician, you may be better qualified to find the problem than your repair shop. Take an ammeter and put the leads in series between the negative battery cable and the battery, you'll obviously have to disconnect the cable from the battery first. If you have more than 50 milliamps, you have a problem.If less, your battery may be junk and won't hold a charge. If more than 50 milliamps, it's time to start pulling fuses and/ or relays to try and isolate the current draw. May be just a stuck relay, give em all the tap test, hit em with your Kleins and see if the current draw drops. Probably something simple. I know schematics would help but unfortunately, not always available.
Bob, I got that far, just don't know without taking the thing apart, what is involved.
I got an idea, probably just a bunch of dc valves, a electric motor for emergency operation. But it works just fine after you jump it. Rather not rip into it, without a schematic, they would sure make it easier.
I'd also imagine that most of them are probably, somewhat alike in the controls, so maybe if I can find any schematic, I can probably work off it.
The other problem lies finding which valve is what. Never took one apart before.