1957 corvette and Halogen headlights

[Theodore K.]

Does anyone know the correct type number for the 1957 Corvette? and the current and/or wattage rating for that headlight. Does anyone know of a Halogen Headlight replacement that will fit the 1957 bezel and what the amperage and/or wattage rating for that headlight would be? The headlight switch has a 13 amp breaker supposedly built in. Will that take the amperage draw of this Halogen lamp. Your help is appreciated.
Ted von Kampen

[Dan D.]

Re: 1957 corvette and Halogen headlights

Ted, there have been past threads on this. Search the archives. But the bottom line is don't do it. There were multiple reports of the switch circuit breaker cycling because of excessive current. There was also a report of the dash becoming hot. If you have old wiring and an old switch, the risk is even higher.
These cars were not designed for Halogen, and the circuit breaker was apparently sized very close in order to protect the wiring. Do you plan on doing a lot of night driving? Most of us do not. -Dan-

[Clem Z.]

Re: 1957 corvette and Halogen headlights

use a relay to power the new headlights that has the B+ power lead connected directly to the battery thru a fused line.

[John H.]

Re: 1957 corvette and Halogen headlights

use a relay to power the new headlights that has the B+ power lead connected directly to the battery thru a fused line.

Correct - that takes the load off the headlight switch - all it has to do is operate the relay, not feed current to the headlights.

[Dan D.]

Re: 1957 corvette and Halogen headlights

Repop T3s are 25% brighter and produce whiter light than original T3s. They are nearly correct, but are pricey at around $100/ pair. If you really want Halogen, then a relay is the only way to go. -Dan-

[Clem Z.]

Re: 1957 corvette and Halogen headlights

i learned the hard way as a set of cibie lights i installed on my 78 chevy fused the high bean switch in the high beam position when i was on vacation in fla.

[Tom P.]

Re: 1957 corvette and Halogen headlights

??????????????????????? If you're referring to current REPLACEMENT headlights, they're ALLLLLLLLLLLLL halogen! Everything I own now has replacement halogen headlights, including my 56, and they are a DIRECT, bolt-in replacement for the stock, original T-3 bulbs. I've been using the replacement halogen bulbs for at least 30yrs with ZERO problems (which are considerably brighter and quite sufficient). So I don't understand the insistant necessity for a relay.

[Dan D.]

Re: 1957 corvette and Halogen headlights

Okay Tom. I am going to buy a new set of T3s. When I get them I will measure the current draw of both the new and the originals and post the results. I also have an old photographic light meter that will measure foot candles (GE type 213. Hows that for ancient history). I will try and measure both lights and see what I get. I should ask Lectric Limited if their bulbs are
Halogen.

Nothing is easy in this hobby. -Dan-

[Dan D.]

Re: 1957 corvette and Halogen headlights

I bought 2 new T3s from Corvette Central - came in a Lectric Limited box - not surprising. I bought from CC as they were $25 cheaper than the LL on-line price. I also called LL and spoke with one of their technical people. He said their lights are not Halogen, the improvements in brightness and color are due to improvements in sealed beam technology. When asked about current draw, his response was "negligible".

How correct are they? Visually they are close, but no cigar. My old T3s have a date code code of 472*, which would be April 2, 1957 - 3rd. shift. Both are the same. This would indicate that they are probably original as my car has a birth date of May 21, 57.

The differences I see are the repos have larger font size for the lettering, and if you look inside the reflector design is different.

I have characterized them electrically and compared them to my originals. I used 12.5VDC to power them and brought the voltage up slowly in order to minimize the stress on my old bulbs. I measured current draw and foot candle power at a 13 foot distance in a darkened room (basement - lights off).

First thing - right off - is the repos are wired wrong. The low and high beams are reversed, which will reverse the high beam indicator on the dash. So they will have to go back. But here is the data I measured.

Bulb Amps. Foot candles

Repro #1:
Low beam 3.73 190
High beam 4.30 210

Repro #2:
Low beam 3.66 155
High beam 4.37 210

Original #1:
Low beam 2.81 40
High beam 3.72 175

Original #2:
Low beam 3.08 95
High beam 3.86 200

This would indicate that my old #1 low beam bulb may be nearing EOL as the current and light output is significantly lower. The new bulbs are difinately not Halogen. Both the color and the light intensity are not Halogen.

In all cases high beam focuses lower than low beam.

The combined current is about 9 amps, so if the headlight switch circuit breaker is 13 amps, then one has about 4 amps of wiggle room if they use Halogen. I don't know how much additional current Halogens draw, but they will be higher.

If these lights were wired correctly, I would be happy with them. I just cannot believe they could screw up simple 3 terminal wiring.
-Dan-

[Jerry B.]

Re: 1957 corvette and Halogen headlights

The Chinese cann't read.

[Dan D.]

Re: 1957 corvette and Halogen headlights

These are USA

[Dan D.]

Re: 1957 corvette and Halogen headlights

I bought 2 new T3s from Corvette Central - came in a Lectric Limited box - not surprising. I bought from CC as they were $25 cheaper than the LL on-line price. I also called LL and spoke with one of their technical people. He said their lights are not Halogen, the improvements in brightness and color are due to improvements in sealed beam technology. When asked about current draw, his response was "negligible".

How correct are they? Visually they are close, but no cigar. My old T3s have a date code code of 472*, which would be April 2, 1957 - 3rd. shift. Both are the same. This would indicate that they are probably original as my car has a birth date of May 21, 57.

The differences I see are the repos have larger font size for the lettering, and if you look inside the reflector design is different.

I have characterized them electrically and compared them to my originals. I used 12.5VDC to power them and brought the voltage up slowly in order to minimize the stress on my old bulbs. I measured current draw and foot candle power at a 13 foot distance in a darkened room (basement - lights off).

First thing - right off - is the repos are wired wrong. The low and high beams are reversed, which will reverse the high beam indicator on the dash. So they will have to go back. But here is the data I measured.

Bulb Amps. Foot candles

Repro #1:
Low beam 3.73 190
High beam 4.30 210

Repro #2:
Low beam 3.66 155
High beam 4.37 210

Original #1:
Low beam 2.81 40
High beam 3.72 175

Original #2:
Low beam 3.08 95
High beam 3.86 200

This would indicate that my old #1 low beam bulb may be nearing EOL as the current and light output is significantly lower. The new bulbs are difinately not Halogen. Both the color and the light intensity are not Halogen.

In all cases high beam focuses lower than low beam.

The combined current is about 9 amps, so if the headlight switch circuit breaker is 13 amps, then one has about 4 amps of wiggle room if they use Halogen. I don't know how much additional current Halogens draw, but they will be higher.

If these lights were wired correctly, I would be happy with them. I just cannot believe they could screw up simple 3 terminal wiring.
-Dan-

I need to correct some errors in this post. I have done more testing and have had several phone calls with a technical person at Lectric Limited.

First of all - their headlights are not wired wrong. They are correct. I had 2 problems in my initial testing. I was using a toggle switch to switch between low and high beam, and the toggle switch I used did not work as I thought, or as most toggle switches do. Second is the LL lights draw more current in low beam than they do in high beam. This is not as one would expect, but it is true and these 2 things combined confused my thinking as to what was low beam and what was high beam. This led me to make some conclusions that were not correct, including the fact that high beam focuses higher than low beam, not the opposite as I stated in my original post.

I also have 2 other 7" (aftermarket - auto store - no T3 markings) sealed beams of 1960 origin. One is GE, the other is Tung Sol. So I characterized them also. As far as current and light intensity goes, my original data is very close to the new data. There were no mistakes there - mistakes were only in which beam I was testing.

BULB BEAM CURRENT FOOT CANDLES

1957#1 Low beam 2.75 50
1957#1 High beam 3.76 130

1957#2 Low beam 3.1 90
1957#2 High beam 3.85 200

1960GE Low beam 3.17 210
1960GE High beam 3.94 200

1960TS Low beam 3.14 150
1960TS High beam 3.68 200

New LL#1 Low beam 4.28 200
New LL#1 High beam 3.72 200

New LL#2 Low beam 4.37 200
New LL#2 High beam 3.66 160


Conclusions:

1. The current (at 12.5VDC) was measured using a digital VOM and the accuracy is very good.

2. The light intensity - measured at 13 feet in a darkened room - was measured using an old photographic light meter and by moving the meter around to try and obtain a maximum reading. This data may not be real accurate.

3. I believe that all the bulbs, when new, probably had similar light intensity, about 200 foot candles under these test conditions, and were the about the same in both low and high beam.

4. The varying light intensity I measured between these bulbs is due to the age of the bulbs.

5. The only noticeable difference between low and high beams is high beams focus higher up.

6. My 1957 # 1 bulb is nearing EOL. In addition to the lower current and light intensity, the bulb is gassy (cloudy on the inside).

7. The technical person at LL did not argue the higher current in low beam. I don't think he knew. It was probably required in order to meet the newer DOT requirements.

8. Probably all new T3s are made by Wagner, with LL being their distributor. My recently purchased bulbs, purchased from CC, are date coded 2007, and the bulbs still at LL are also 2007, which leads me to believe a run was made back them and they are still using that stock.

9. Per the LL person, all bulbs are/were hermetically sealed, which in my opinion they would have to be. So I did not understand how that seal could fail, based on age alone, and how sealing the terminals with epoxy, as has been suggested on this forum, could sustain a hermetic seal. Per LL, he claims the terminals were soldered coated, and solder being porous would slowly let air in. The varnish coating on the back of the terminals would also fail with age and weaken the seal.

10. These new bulbs are not Halogen. They are still incandescent. I don't really believe they are brighter than older bulbs, but may be whiter light and probably focused differently. I have no way of measuring this and I don't know what DOT requirements changed to mandate this. My little light meter uses an old selenium cell to measure light intensity, but is both color and cosine corrected, and good for spotlight measurements as well as natural sunlight.

11. Combined current draw for 2 newer bulbs in low beam will be 8.5 to 9 amps, so if the light switch circuit breaker is 13 amps, then the newer bulbs are still in the acceptable current range without interrupting. For Halogen lights, this margin will be less as they will draw more current - I don't know how much more. Halogen will also further burden 25 amp DC generators, keeping in mind you still have the ignition system, tail lights, instrument lights, and maybe the radio and heater blower, all drawing current. Plus the old DC generators do not produce charging current at low engine RPMs and is worse yet with the larger pulley used in solid lifter engines.

12. I am done with T3s. I hope this information will be of help to those of you with headlight issues, or thinking about using Halogen bulbs. It seems there is more to headlight technology then one would think.

-Dan-