BMW 740il just cranking, won?t start, after replaced 1 ft. hose under reservoir by shop

BMW 740il 94? just cranking, won?t start, after replaced 1 ft. hose under reservoir by shop.

Urgent, repair shop closed for weekend, car is in front a museum.

Auto mechanics Replaced 1 ft. hose under reservoir, put on engine cover while running, drove 10 blocks and parked, 5 minutes later, won?t start. AAA came and tried jump, no luck. Towed back to shop.

Mechanics tried jump, also failed. He did found the battery connector under back seat loose. He did some connector twist ( 2 minutes) around engine block and engine started. He think my battery weak, and kindly loan me the new battery while recharge my battery( Interstate). I did tried to restart car few times, all ok.

Then I drove 10 blocks to a museum, an hour later, it just cranking, won?t start again.

History:

BMW 740il 94? has 150,000 miles, always start strong.

When ?coolant temp? sign on last week, I came to this shop. He checked and replaced waterpump, then

Replaced heater hoses-Octopus host and 1 ft. hose under reservoir-Right side, drove 20 blocks parked, still leaking coolant.

Back to shop, Mechanics replaced 1 ft. hose under reservoir- Left side, then Starting problem pursist?

Thank you in advance for advises to save the weekend;-) All the best.