Hi
Looking for a bit of advice with a real head scratcher.
The other day my car started to be noticeably low on 'umph' and then stalled a couple of times when I put my foot on the clutch.
I took it to a local mechanic who thought it'd be a vacuum leak.. which it wasn't, he then checked fault codes and nothing.
He thought it was running ok when he had it, so I got it back.
Within a couple of days of getting it back it's now developed the following faults

- blower working but no heat, it's constantly on cool.
- full beam wasn't working but then suddenly started working whilst I was driving.
- pinking when driving up hill ( never done this in 7 years I've had it ).

Pretty sure this an electric fault because I've had an issue show up previously where the 12 volt circuit was randomly playing up ( I got a code on the dash clock ) plus the blower would not direct air to the footwell and the headlights and rear wash wipe stopped working. I sorted this out by disconnecting the battery for half an hour after a good Samaritan on this forum told me it was a 12 volt circuit issue and then it ran roughly for a few days after and was then fine.
This was a couple years ago and has happened again a couple times since ( always sorted via battery disconnect routine ).
Obviously I'll try that again but even if it does work there's obviously something amiss here.

Anyone got any thoughts?

Any help gratefully received.