This says to me the compressor can't get any pressure into the system. Not tried it but assume there's a way to disconnect the output connection and see if you can stop the air with you thumb over the hole. Assuming you don't have a pressure...

It is known to fix some things on l322 so it's always worth a go.

Have you tried the battery disconnect for half hour reset procedure. And shorting the terminals together (NOT BATTERY TERMINALS) to drain residual power from the ECU's?

^^^^ What he said. I believe it's underneath it.

Big black box on top of right side inner wing.

A good number of us have already fitted the larger battery so what issues would you expect?

These cars are very power hungry, the right battery is the biggest that will fit in the hole

The permanent live on 7 pin systems is in the second 7 pin connector denoted 7S.

Are you sure that the MAP sensor should have a 12 volt supply? If not and you applied 12 volts the sensor is probably toast.

@Varks74 Just a thought. Have you tried swapping the fibers over on the display in case they have accidentally been switched round?

It was easy for me cos I was using a 4 post lift but unless you're very very skinny I doubt you'd get under it. Maybe jacking it up and using axle stands is an option.

If the car is a P38, all the S connections are available in the left rear quarter behind the trim and 7 core cable is fine. There is a grommet at the base of the well below the connectors that can be used to route the cable. I can give you all...