Many posts about our 60’s era cars electrical systems that discuss alternator upgrades, bulkhead bypass, amp gauge bypass, relays for headlights and LED conversion. All suggesting various changes to the stock electrical systems of these cars.
Thought it would be interesting to research some facts on the published specs for the incandescent lamps these cars came out of the factory with as well as some modern optional LED lamps available as substitutes / replacements for what was factory supplied. You probably never thought much about the wattage and current draw of these stock lamps, I know I never really did until I started doing some research. Based on these published specs,decisions on what LED types would be the best choice for brightness and reduced current draw without making any changes to a cars stock electrical system was helpful. Among the various manufacturers, spec sheet data for similarmodel incandescent lamps had some small insignificant differences that are really not relevant.
Note:
Values shown for are for a single lamp. A- is current draw in amps at 12.8 VDC
4001 “Sealed Beam” lamp 50.0 watt 3.90 A
4002 “Sealed Beam” lamp 37.50 watt 2.92 A
H-4001 “Halogen” Lo beam 50.0 watt 3.90 A
H-4002 “Halogen” Hi beam 110.0 watt 8.59 A
Holley “Retro Bright” LED headlamps
Lo beam 25.0 watt 1.95 A
Hi Beam 30.0 watt 2.34 A
1034 Dual filament, Tail & rear turn and fnt amber marker/turn signal
Lo brightness 8.3 watt .648 A
Hi brightness 23.0 watt 1.79 A
1157 Dual filament, Tail & rear turn and fnt amber marker/turn signal
Lo brightness 8.30 watt .648 A
Hi Brightness 26.80 watt 2.10 A
There are many variations of LED lamps that directly replace either a 1034 or 1157 incandescent lamp. Typically, the LED replacement specs vary from 1.5 to 3.8 watts. They have lower current draw for the brighter filament for turn signaling and braking. On average, that current is below ½ Amp for a single LED lamp. For my 66 Charger, I decided on these Red LED’s (link below, available on Amazon) to replace the six across tail lights, I retained the incandescent 1157’s on the front ambers because that, along with the 3 LED’s on each side was enough current draw that the original mechanical-thermal flasher worked as normal and changing to an LED flasher unit was not required. Your situation may not be the same as mine with a lower tail lamp count or less less current draw unto the flasher unit. These red LED’s decided on are at least 2 x brighter in daylight than the incandescents were.
https://www.amazon.com/dp/B0CLXYDM4C?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
Also many variations on LED headlamp offerings available. I chose the “Holley Retro Bright” as they were truly “Plug N Play” for my Charger and required NO mechanical or electrical modifications. Not cheap though ! Significant increase in light output and choice of color temperature, available in cool white or warm white. The latter is much closer to that of the 4001 & 4002 incandescent headlamp. They are significantly brighter. too.
https://www.holley.com/brands/holley_retrobright/
If you are looking to upgrade to get better day and night visibility for your classic, LED’s are the way to go. I have been very pleased with the changes made to my 66 Charger.
