Check: Connect inspection lamp on relay (3) to 87 a and
earth.
Pull cables off temperature switch (2).
Switch on ignition.
Inspection lamp must go on.
If the cable with has been pulled off is connected to
earth, the inspection lamp must not go on.

Remove relay from brake servo.
Pull off cables.
Note when fitting:
green/white 30/51
brown/black 85
green 86
green/yellow 87 a