I found a Vector 3 Million in a house that I just bought. Though it is fully charged, I am unable to turn on the twin searchlights, though I am able to turn on the two sidelights. I've placed the switch on single and twin and pressed the trigger on the pistol grip, but the lights do not turn on. Is there another switch that I need to turn on? I don't have the operating instructions and have not figured out how to get to the bulbs.

Most likely that is the issue.

The battery life for these lights are for about 2 years at the most if left uncharged. The best way to determine if you need new a new battery or batteries would be to dismantle the light, remove the batteries and check the voltage with a volt meter. If they are dead, you may be able to fine a suitable replacement at: http://www.batterymart.com/c-04-12-volt-sealed-lead-acid-batteries.html

Baccus just bought Vector from Black & Decker (Sept. 2010)
Looks like flashlight model # VEC 139BW but a different color. (Mine is White w/blue trim.) There is a battery in the top & one in the bottom, replace them at the same time. If I can find several battery stores in Buffalo you should be able to find a local battery store there.
Baccus- 877-571-2391 for main beam, area light no longer available. Try to find local distributor & save shipping charges.

You can get the bulbs fron Black and Decker, they service and repair all Vector products.since they were bought out in 2006. www.dewaltservicenet.com You could also have a defective battery or charger, it should take about 10-12 hours to fully charge.

Vector was acquired by Black & Decker in 2006, but DeWalt carries replacement parts. I searched for yours and found this:

http://www.dewaltservicenet.com/Products/ProductDetails.aspx?pid=69407&tid=16417

I just bought 3 from "The Bulb Man" 2207 Elmwood Ave. Buffalo, N.Y. 14216 (716) 875-2852. He had to order, they came in in about a week. They work fine but bulb has no blue tint, I'm starting to look for the area light when I found this. Bulb, base & wire is all one piece. I think I paid $12-14 for all three a few weeks ago. (Aug 2010)

While it could be the battery, it could also be the internal charger in the spotlight. When you plug it in, it bypasses the charger and uses the connected power. However, it is likely just a bad battery. The batteries only last 3 years in an ideal setting and since these lights are typically only used certain times of the year, the batteries discharge and go bad. New batteries can be found at: http://batteryinternational.com/spotlight-batteries-vector-battery.html

It depends on what voltage the internal battery is. If it's a 6 volt, the charging voltage will be a little higher, close to 6.5 to 7 volts. Most of these spotlights are 6 volt. New batteries can be found at Battery International: http://batteryinternational.com/spotlight-batteries-vector-battery.html

6 Volts, here is info from site.
VEC127Y
VECTOR SPORT SPOT 1 MILLION CANDLE POWER CORDLESS-RECHARGEABLE SPOTLIGHT

• HIGH CANDLE POWER QUARTZ HALOGEN BULB DELIVERS A BRIGHT AND TIGHT BEAM
  
• AREA WORKLIGHT IN HANDLE PROVIDES UP TO 15 HOURS OF LIGHT WHEN FULLY CHARGED
  
• PROVIDES CONTINUOUS SPOTLIGHT USE FOR UP TO 25 MINUTES WHEN FULLY CHARGED
  
• HIGH IMPACT, BREAK RESISTANT ABS AND POLYCARBONATE HOUSING
  
• TOUGH, WEATHER RESISTANT AND BUILT FOR RUGGED OUTDOOR USE
  
• REPLACEABLE 6 VOLT, 6 AMP HOUR, NON-SPILLABLE, SEALED BATTERY
  
• LOCKING TRIGGER FOR ON/OFF LIGHT CONTROL
  
• INCLUDES AC AND DC CHARGING ADAPTERS
  
• INCLUDES BUILT IN HANDS FREE WORKSTAND
  

It is the battery, I have a similiar Vector light for a few years and tried re-charging the battery but only the little LED light would come on. I have another Vector light, same model and switched batteries from the worjking one to the non-working one and now it works fine.

I then proceeded to purchase a new battery for the non'working one and when I arrived home I installed it and turned on the main light, still won't turn on, I tried the LED's, they work. I figured maybe the new battery needs a good charge so I plugged the charger in and charged the light for 12 hours, still no main light.

I guess the new battery is defective, so now I will return it and exchange it for another one.