Vauxhall Zafira near side main beam not working, but off side works ok new lamps fitted

You will need to start by checking if you are getting power to the lamp that is inoperative and take it from there

Have voltage at Lamp holder

When you say you have had new lamps fitted , do you mean new headlamp units or bulbs ( if that year does not have LEDs ).

New Bulbs

Take out your bulb and test or swap with other side which is working . Not the first time a new bulb has been faulty . If o.k and getting power , only other thing it needs to operate is an earth .

I have swapped the lamps and both work on the offside, main beam

have been advised possible problem may be the Relay, but do not know where this is situated

If you have power , bulb is o.k , the only thing left is the bulb holder and an earth / ground connector wire from plug

Cant be a relay if you are getting power to the bulb