I went to test a 68 fog light bulb by taking a couple of wires and connecting them to a battery and it suddenly started to smoke inside the light. Should I have not gone directly to the battery? Is there some sort of resister in a normal setup? Thanks
Naw - just burned the light out IMHO- it's kapootski. The circuit does goes through a circuit breaker of about 10 or 15 amps, but still 12 volts. Just like testing a horn or wipers - connect them to + and - , then see if it works.
The smoke you saw was the tungsten filament frying due to heat buildup - resistance- in the tungsten filament itself. Resistance was caused by a thinning or crack in the filament. The thinning made it hard to carry the current from the battery, so it heated up and burned out at the thinning/crack point.
New bulb time.
Also make sure it was not a 6 volt farm tractor bulb. A friend gave me some old acc. lights with the rubber housing that came from a tractor, I tested them out the same way and the did the same thing. Took the bulbs out and on the back it said 6V