Your electrician has done the right things so far, Ken, starting with making sure that the battery is charged and being charged by the alternator and that the car is earthed (grounded) properly. Those are traditionally major causes of this type of problem, but unfortunately there are many more possibilities in a modern car with its electronics. My first thought is that the functions you’re having trouble with are all controlled by the car’s body computer. So I think that’s where your electrician should start looking next. These computers can develop software and hardware faults that allow for these random and intermittent problems. So maybe borrowing a body computer from the same make and model and seeing if that fixes your problems (and at least ruling out the computer) is a cost-effective way forward.
I’d also be having a chat to the workshop that replaced the steering rack to see if there’s any way that a connection or sensor related to the on-board computer could have been bumped or damaged during the rack-replacement process. It would certainly be a coincidence (and it’s possible that this is exactly what this is) if these problems started straight after the repairs, no?
