Quote:
Originally Posted by vertigto
Silly question...how much of a difference is there if you don't use relays with sealed beam halogens?
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Quote:
Originally Posted by Bill Hanlon
Depends on how much loss you have in the headlight wiring now.
If you can get to the plug on the back of the passenger's side headlight WITH THE LAMP PLUGGED IN...
Attach a voltmeter black lead to ground.
Turn on low beam headlights.
With the engine running at a high idle use the red lead to measure voltage at the battery + terminal. Record this as "measurement 1".
Now touch the red lead to left pin of the socket of the passenger's side right outer headlamp. Record this as "measurement 2".
Now touch the red lead to right pin of the socket of the passenger's side right outer headlamp. Record this as "measurement 3".
Now touch the red lead to center pin of the socket of the passenger's side right outer headlamp. Record this as "measurement 4".
Report the 4 measurements.
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As Bill mentions, it really depends on how much parasitic loss you are seeing at the bulb.
The way the factory harness is arranged, you send power from the battery, to the dashboard harness and on to the headlight switch. That switch then routes power from the switch back through the dash harness, across the bulkhead connector and through the forward light harness where it reaches the bulbs.
Sylvania doesn't list there lumens per watt, but common information on sealed beams has them at upper 6 lumens per watt, google says 6.6
For a 40 watt sealed beam you're looking at 264 lumens...assuming you're achieving 40 watts at the bulb. That's roughly the same as a decent hand-held flashlight. The 60 watt high beam is producing close to 400 lumens. Much more appropriate for being able to see in the dark, but you're running on your high beams all the time and again assuming you're pushing 60 watts to the bulb.
Since volts and watts are measured together V+A=W if you reduce voltage, you reduce wattage. Lets say your alternator is pumping out 13.8 volts through the system. To reach 40 watts at 13.8 volts would require roughly 2.9 amps.
Now imagine you're still pushing that 2.9 amps through the system, but your voltage at the bulb has dropped to 12.5. That gives you 36.25 watts on your low beam, now producing just shy of 240 lumens. Now your backyard flashlight connected to the front of your car has old batteries in it. It's a 10% drop in light output.
All this of course is a gross over-simplification of what is truly going on, but you can see that the more load you have on the car's harness, the worse shape the wiring and connectors are in, the more voltage drop you're going to have at the bulb and that all still assume you can carry the amps as well.
FWIW a quality LED will produce about 100 lumens per watt. A 30 watt LED should produce close to 3000 lumens and because the light is directed there's very little unrealized lumens like you get in a sealed beam. You lose about 30% of total lumens in a sealed beam to about 10% loss in an LED.
If you're dodging dear in your area, which headlights do you want on the front of your car?