no headlight or side light o/s front..vectra 96/n?

Check the ground of the light! If thats not effective you wont get a bulb to operate. A quick check here would be to use a bit of insulated wire, connect one end to the negative terminal of the battery. Then touch the other end of this wire on the outside/ground of the bulb when you have turned the lights on. If the bulb iluminates, it's a ground issue.
Just make sure you dont touch the positive side of the bulb with the lead as you'll blow the fuse, at the very least, destroy your wiring loom and battery at worst.
A safer method may be to use a voltage indicator to test for an incomming 12Vdc supply when you turn the lights on.

Mike
August 2005