Not on DC you can't. You can use a DC/DC converter, but they're > £200 to get 30Watts. A new 12V bulb is £7.
What about making one with an 7806, piece of circuitboard, some resistors and it's there. I've had one in my cars couple of years ago for powering a portable device
Possible, but you need to provide 30W of power. Any kind of voltage regulation is going to get mighty hot. Not really worth it just to drive a light bulb!
@grub - Sorry I didn't explain that very well. When you buy a PAR lamp you get the whole lot - front glass, rear reflector, and the bulb sealed in the middle. As long as you can get to the terminals on the back, you replace the whole thing. It seems a bit wasteful, but because it's sealed the reflector doesn't get dirty and can't corrode, and you don't have to worry about touching the lamp with oily hands unlike a conventional halogen lamp.
@MarecT512 - sorry for the late reply - just got back from a weekend away - many thanks for the info matey - I didn't realise that I could get a whole new sealed beam unit to fit my old lamp, or that they were so cheap! I will order a new sealed beam unit from the link you posted up - 12v bulb, no messing about, job done. Thanks again matey, as soon as I get this fixed, I will post some piccies.
ok, managed to get my local electrical factors to get me 1 4405 lamp in - £6.47 & no postage costs - result! Fitted the searchlight and it looks a treat! Just need to wire it in now. It's earthed through the body, but can anyone recommend where to take the 12v supply from, bearing in mind it's 30W & would need to be fused I suspect. thanks ps - i'll post up a photo when I can sus out why my photobucket account won't let me upload any more photos?
Presumably, you only want it on when it's dark? Take the supply from the top of Fuse 1, which'll go live when the sidelights are on, then through the switch. F1 is 8A, which should be fine.
Take a look at the wiring diagram: http://www.thesamba.com/vw/archives/info/wiring/bus_8_71_1700.jpg ...that one is for a '71/'72, but they're all similar although earlier busses have fewer fuses. Disconnect the battery before starting any electrical work. If you want a permanent live (ignition off), take a feed from the back of the fusebox opposite the thick red/white wire (in the diagram, it connects to the bottom of fuse 9, and is linked by a brass bar to the bottom of fuse 8). Take your live feed from the top of either of these fuses (fuse number might vary - so look for that thick 6mm2 red/white wire - it is the main power feed to the front and comes from the starter solenoid, which is directly fed by the battery). If you want an ignition switched live, take the feed from the top of fuse 11 (which also supplies the dashboard instruments and the indicators).
All wired up & working now - thanks peeps - put some piccies up in a separate thread if anyone's interested!
