45/35 watt headlights

[Michael L.]

Does anyone have a source for 45/35 watt headlights? I'm running 60/50 watts ( only wattage I could find ) and I'm tripping the breaker on my headlight switch. I do have the option of running relays up front with power off the battery and keeping the 60/50's or??? Any lower wattage bulbs out there?

Thanks in advance,

Mike L

[William C.]

Re: 45/35 watt headlights

I take it you are looking for 6 volt versions?

[Michael L.]

Re: 45/35 watt headlights

The car is 12 Volt, the ST-12 shows '53-'54 as 45/35 watts and same for '55 but no mention of volts. I assume the '55 ran 12V 45/35 watt headlamps. Or ??? Thanks! Mike

[Michael L.]

Re: 45/35 watt headlights

Just got a reply from an Ebay vendor stating he does not know wattage on his reproduction T3 bulbs, and he suggested I just " use a larger fuse"

Yikes!

[Robert J.]

Re: 45/35 watt headlights

Mike; I'm running a set that is 50 watts with no problems ......yet......I'm till looking for one more early 55 steel back bulb. Bob

[Michael L.]

Re: 45/35 watt headlights

I gave up looking. I'll run my 60/50 watt lights. Just wired in a set of relays. Not stock, but my car is a driver and when the temps are close to 100 degrees, I like driving at night. Waiting for a new switch and I'm good to go...

[Robert J.]

Re: 45/35 watt headlights

I know what you mean about the 100 Deg. We live up in Lake Almanor which is about the same as Reno. If I run into some extra headli8ghts I'll let you know. Bob

[Michael L.]

Re: 45/35 watt headlights

Thanks Bob, but with the relays, I should be fine with the 60/50 and have full power. I know it is not factory, but the dim lights at night and the strobing were a pain...

[Jack H.]

Re: 45/35 watt headlights

The '53-54 Corvettes were all 6V systems. When the V8 made its debut in '55, those cars went to a 12V system with VERY few buyers opting to purchase the base 6-cylnder engine car with its 6V 'hold over' electrical system.

GM headlight switches have LONG included an internal circuit breaker as an electrical fire threat measure. If you're popping the breaker in your HL switch, you ARE drawing too much current for the application!

In general, a properly designed and implemented 6V circuit will draw TWICE as much current as its 12V equivalent. That's a consequence of energy conservation...

So, when the transition was made from 6V to 12V, a number of discrete component changes were made to accommodate things. The filament resistance of a 6V lamp is different than its 12V counterpart. The current profile of the internal circuit breaker in the HL switch had to change too.

Problems can/do surface when people 'brute force' change a given car from a 6V to 12V system. I'd say you have two choices: (1) go back to the car's original 6V system (including headlights, HL switch, Etc.) or (2) make sure ALL of the components used on your 12V conversion car are 12V rated....

[Michael L.]

Re: 45/35 watt headlights

Jack, my '55 is a 12 volt car. I'm using a reproduction headlight switch, which according to the vendor is prone to tripping the breakers even with a slightly higher wattage bulb. So, I ordered a new switch, a new dimmer switch and just for grins wired in relays for low and high beams and ran the power right off the hot lead on my starter. I used 12 gauge wire for the power with a 30 amp fuse in the line. Once my switches get here, I'll connect them and see what having the relays does to the strobing problem. I gave up looking for 45/35 bulbs, I'll just use the 60/50 currently in the car and hopefully enjoy my night time driving more with brighter lights that don't quit on me every 2-3 minutes due to an overloaded switch.

Mike

[Jack H.]

Re: 45/35 watt headlights

Gotcha! If she's a '55, the odds are it WAS a 12V car and you should be good to go with 12V headlights. I'm kind of surprised that the supplier said his reproduction HL switch was 'touchy' with respect to internal breaker load threshold.

In general, designers 'build-in' some level of safety margin into their selection of fuse compo9nents. It's a long complicated story, but the headlights are purely resistive, and the general rule of thumb would be a design safety margin in the 50% range with normal blow characteristics. Other circuits (circuits with energy storage components like heater blower fan, WSW motor) would use different design safety margin criteria.

But, it looks like you've put your finger on the problem(s): characteristics of the reproduction HL switch combined with the specific HL lamps you've installed.

The only thing I can add is this. The wattage rating of a lamp characterizes its electrical INPUT profile (how much current/power does it draw). The lamp's output characteristic is spec'd in terms of candle power or lumens.

It's the second issue you're trying to improve on. Not all lamps are alike. Its the lamp's filament characteristic that defines overall power efficiency. Today's tungstun 'alternative' filament technology is WAY more efficient than that of the factory original lamps from that era.

If you have time, you might want to look for driver head lamps that'll fit and function in the same socket which are more efficient, but still fall within the factory original power consumption profile...