- that there is a gap of at least 2 mm between the spare wheel and the control rod, - that the ventilation pipe (19) does not touch the delay device rod (20). There must be at least 2 mm between them. 7. Put the circuit under pressure, and run the engine idling speed during adjustment. 8. Adjustment of main headlamps. Use apparatus of type « Regolux» or «Regloscope». Ensure that the car and adjusting apparatus are in alignment.