One of the main advances in car safety design has been in the headlight sector. Bigger, brighter and they last longer and of course more expensive. The key to the brighter longer lasting lamp is the Quartz-Halogen technology. Unlike the old Tungsten Vacuum lamps and sealed beams the filament burns in an atmosphere of Halogen gas and the lens contains a large amount of Quartz rather than Silica. In the old style head lights the vacuum, or absence of oxygen, prevented the filament burning out but it does not stop it boiling. As the Tungsten boils some of the vapour condenses on the inside of the lamp and blackens the glass preventing light from exiting. As more Tungsten boils and migrates from the filament it becomes thinner until it can no longer take the current and like a fuse it blows.
The sealed beam tackles the problem in the American, make it bigger, way. The larger surface area of the inside of the sealed beam, the back of the lens and the reflector, has to be covered with considerably more Tungsten deposit to form a layer deep enough to drop the light level. Consequently a thicker filament can be used which of course lasts longer. The real cunning comes about with the introduction of Quartz in the making of the glass. Quartz will not allow the Tungsten vapour to condense on its surface. With the help of the Halogen gas and the antisocial properties of the Quarts the only place the vaporised Tungsten can settle is right back where it comes form, the filament. This means the inside of the lens and reflector stay clear and bright, while the filament stays the same thickness. These quartz Halogen lamps therefore maintain the same output level from the day they are installed to the time they break, unlike the Tungsten vacuum ones which start to dim from day one.
Fig.1 The Two Changeover Relays Method
It is possible to take full advantage of this technology without distracting too much from the originality of your Early Falcon. Changeover kits are readily available at most accessory shops. They normally include two headlights a headlight relay and some good quality automotive wire and a 20 amp in line fuse holder. However if you already have the lamps all you will need is the fuse holder, two10-15 amp changeover relays, a 3 amp diode and a hand full of crimp connectors. Although the purpose built headlamp relay is the way to go, they can be ordered from accessory shops. It’s also a good idea to get, from the wreckers, the Ford plugs and pieces of wire that are between the loom and a headlight, this will save you having to alter your original loom.
Firstly mount the Headlamp or Changeover relay to the engine bay between the Battery and the shockie tower and the other relay (not required with Headlamp relay), within 50mm of the existing headlight cable loom plug making sure you have good electrical grounding. On a lot of plastic relays you will have to run a cable from the ground terminal (bosch 86) to the car body.
Fig.2 The Single Headlamp Relay Method
Using the parts from the wreckers, cut each power lead allowing approximately 100mm of cable to remain with both the lamp socket and loom plug. Do not cut the ground lead off the lamp socket. Then (if you are not using the Headlamp relay set-up) twist together the bared red wire of the loom plug, the sliver band end of the diode and a piece of new cable and crimp them. Now do the same with the green wire of the loom plug, the other side of the diode and another colour piece of new wire. This loom plug will replace the plug and lead feeding the passenger side headlamp with the green lead feeding the coil contact on the Changeover relay (bosch 85) and the red to the coil contact on the second relay (bosch 85). If you’re using the Headlamp relay simply extend the red and green leads to reach the S1 & S2 contacts as shown in Fig2.The in-line fuse will need to be connected between the Positive battery terminal and the Common contact (bosch 30) of the second relay (or the B terminal of the Headlamp relay Fig2). While the Normally Open contact (bosch 87) of that relay will be connected to the Common contact (bosch 30) of the Changeover relay.
Disconnect the lamp and leads at the loom plugs and remove the original lamps plus the wires. Remove the three small Philip’s head self tappers around the chrome ring at the front of each lamp. This action will allow the sealed beam unit to be released from its cradle. Clean and paint the cradle if required then reassemble with the QH unit and refit. Then using some of the new cable and the in-line connectors, extend the two sets power leads from each lamp socket to the contacts on the Changeover relay, (dip bosch 87a, main 87) on the Headlamp relay L1 and L2. If you made S1 dip then make L1 dip.
Re attach the ground wires from the Headlamp sockets to the car body, again making sure of good contact then test the system by turning on and dipping the lights in the normal way. The driver’s side socket from loom to lamp is not used in either set-up but make sure the bare terminal does not come in contact with the car body.
© BigH 1998
DISCLAIMER
While this method has been tried and works, NO responsibility will be excepted by the Author, the Club or any of its Members.
