A Brighter 74 Lamp

I was having trouble seeing the turn signal indicator in my 1979 Alfa Romeo Sprint Veloce. Though I am relatively old if you’re young, I didn’t want to look that way driving down 101 with my turn signals on.

When the original thermal turn signal flasher gave up, I replaced it with an electronic flasher. With the engine off I can hear it clicking very clearly – I can’t hear it while the engine is running unless the fuse box is open and I stick my head next to it – not a good driving position since the fuse box is just above the floor.

Probably 40 years ago, I made a turn signal amplifier using a 555 integrated circuit and a Mallory Sonalert. It was annoying, sort of like the beepers that some vehicles have when they’re backing up.

I started looking for a brighter lamp for the turn signal indicator that is mounted below the tachometer. The OEM lamp is a 74 Miniature Indicator Lamp – 14 Volt – T1-3/4 Sub Mini Wedge Base. In bright sunlight, it’s difficult to see if the OEM lamp is flashing. I found an LED replacement lamp that is essentially a SMT LED stuck on the end of a plastic tube with a diode and resistor to drop the voltage. It had the necessary wedge base. I had to file the sides down a little so it would fit in the lamp holder, but it was worth the $5.50. It’s bright enough to see in direct sunlight, but not so bright that it’s too annoying at night.

4 Replies to “A Brighter 74 Lamp”

  1. I bought them on eBay. superbrightleds.com has them too, complete with specs. I wouldn’t pay more than $2-3 for them. You also have to remember that you can not control the brightness of the LEDs like regular lamps.

  2. Sounds pretty gnarly. Hopefully you might put together a hobbyist/
    gadgeteer notebook of this and other projects, kind of like a Forrest
    Mims type notebook that people can buy to guide them into building
    and modifying tech devices, kind’ve a Nerd’s cookbook. All of my
    “mods” seem to involve duct tape and serial visits to the Wally,
    their brief lives ending in debris fields and expletives.

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