380 wont start on hot days . No problem on cooler days.
Nothing happens when you turn the key on hot days.
I'm guessing a bad connection some where.

I've read that the ignition lock often fails on these.
Have a search on the forums regarding this matter. There is a how to on replacing it

pitmac, on hot days when it does not start, is that from a cold start or warm start? If cold start then I don't know however, if warm start, it could be a sticky starter motor solenoid.

from a cold start.