G`day ,
around 20 yrs ago i replaced the switch and at the same time fitted relays , one for each light because there are 2 circuits .
Mid last year low beam was working and not and then not at all , because of the relays the switch only switches and doesn`t carry what lets the smoke out , but as i have another new switch .
To get to the point , all a i did was clean the contacts in the old switch still fitted and have had no problem with low beam since .
The new switch sits in the shed with the other spares that stop things failing .

