280Z LED Conversion Part 2

Continuing from part 1, this is the start of installation and results of the LED conversion. I ordered a small bunch of LEDs to get a feel for what brightness I’m looking at since the website I ordered from has somewhat confusing ‘relative intensity’, ‘brightness’, and ‘lumens’ listed for each bulb. Not to mention the prices seemed to fluctuate independently of any of those values so it wasn’t as simple as ‘find the most expensive ones’.

For the first part of the conversion I ordered just 6 bulbs. The Type 97 and Type 89 replacements for the front and rear side markers and the two license plate lamps, respectively. They all use a BA15S base (1156), but the bulb is much smaller. I went with 15 LED license plate bulbs since the bulbs don’t face outward. In retrospect the 15 LED bulbs would have been nice for the side markers as well, but the 9 LED ones I got are at least as bright as the incandescents, probably a tad brighter.

9 LED vs stock Type 97:

 

Incandescent (left) and 15 LED bulb (right)

 

Before:

After:

If I had to do it over again I’d get the 15 LED bulbs for all the clearance lights instead of the 9 LED as they are a bit brighter and have better coverage. But they are still brighter, in my unscientific opinion, than the stock filaments.

Satisfied, I ordered some more bulbs:

The contents being:

  • 2 67-R15 Red (rear tail lights)
  • 2 1157-A45-T 1157 Amber (front combination lamps)
  • 2 1157-R45-T 1157 Red (rear combination brake/tail lights)
  • 2 1156-R45-T 1156 Red (rear turn signals)
  • 2 CF13JL-02 (3 Pin Zero-Load “Japanese” Flasher)

The brake and tail lights are slightly brighter, but come on much faster. The 67-R15s could be replaced with something even more bright but it’s not a big deal. I took a few photos before and after but it’s really hard to tell. However, here is one side-by-side comparison shot:

The left side is the stock tail light bulbs and the right is the new LEDs (67 and 1157).

Once you replace the turn signals the stock flashers will give up due to lack of current. This is fixed by replacing the stock flashers with these “zero-load” flashers. The stock ones depend on enough current to heat up an element and warp it, at which point it triggers by bending and hitting the contacts. This is why if bulbs are out the flash rate is different, or it stops flashing all together. Anyway, these “digital” flashers just happen to fit perfectly with the stock harness. All that’s needed is an extra ground.

The stock turn signal flasher is attached to the steering column, near the pedal mounts:

The hazard flashers is above the ECU and ignition relay:

Wiring both of them up is easy as the B and L terminals match up fine with the stock female plugs.

The wires (on a 1977 CA 280Z) match up as follows:

  • Turn signal flasher
    • W -> ‘L’ (Load, not blue like in the FSM)
    • G/Y -> ‘B’
    • E is the new earth/ground you’ll have to run.
  • Hazard flasher
    • G -> ‘L’
    • R/W -> ‘B’
    • E is the new earth/ground you’ll have to run.

Unfortunately there weren’t mounting tabs on them, but a couple zip ties and it’s good.

And that’s it. I measured the actual amperage before and after (just for the parking and tails), and it went from 1.5 A to 0.5A (33%), with 0.5 A of the dropped attributed to the tail lights alone. Not as a big as I thought but anything to reduce the load on the stock combination switch is good. That’s 20W down to about 7W. My initial calculations relied on the listed wattage for the bulbs, which I’m guessing is based on the maximum current draw which would be when the bulbs are first turned on. That’s down over 90%, which translates into my alternator not pulling down the idle when I first switch the lights on.

280Z LED Conversion Part 1

My 280Z isn’t what you could call “modern” in the electrical department. Originally, it came with an externally regulated alternator, fusible links, incandescent bulbs, and very few relays. The design inhereted a few things from Lucas eletronics, which is not a good thing. Regardless, it was fairly normal for the time. I’m glad there are no vacuum operated things, like some makes. The most electrically obtuse part of the design is the lack of relays. So, all the current for the headlights, parking lights, turn signals, and brakes goes through the individual switches for each. So, not only is there a significant voltage drop by the time the bulbs actually see any current, the switches are very prone to corrosion and failure. Sourcing a replacement column switch is getting harder and harder.

Solutions to this problem? Add in new relays for the lights to significantly reduce the load on the switches, and/or add LED lights to reduce the current draw of the lighting system altogether.

I’m opting to do the latter for now. The power savings are calculated as:

1977 280Z

  • 2 50W/40W headlights
  • 4 Type 97 (1156) 8W bulb side markers (2 amber, 2 red)
  • 2 Type 89 7.5W license plate bulbs
  • 2 Type 1157 23W/8W Stop/Tail lights
  • 2 Type 1157 23W/8W Front Park/Turn signal lights
  • 2 Type 67 8W Rear tail lights
  • 2 Type 1156 23W Rear turn signal lights
  • 2 Type 1156 23W Reverse lights

Incandescent bulbs:

  • 1156 – 23W * 4 = 92W
  • 1157 – 31W * 4 = 124W
  • 67 – 8W * 2 = 16W
  • 89 – 7.5W * 2 = 15W
  • 97 – 8W * 4 = 32W

279W total (not including headlamps). Granted, that’s with the brake lights depressed, in reverse, with the lights and hazards on. A more typical wattage would be 95W.

LED Bulbs

Sidemarkers:

  • 97 (9 LED 67-x9 Amber) – 0.5W * 2 = 1W
  • 97 (9 LED 67-x9 Red) – 0.5W * 2 = 1W
  • 89 (15 LED 67-x15 Red) – 0.5W * 2 = 1W
  • 1156 (45 LED 1156-x45-T Red) 0.14W * 4 = 0.56W
  • 1156 (45 LED 1156-x45-T Amber) 0.16W * 2 = 0.32W
  • 1156 (45 LED 1156-x45-T White) 0.16W * 2 = 0.32W
  • 1157 (45 LED 1157-x45-T Red) 0.165W * 2 = 0.33W
  • 1157 (45 LED 1157-x45-T Amber) 0.195W * 2 = 0.39W

4.92 Watts, and that’s at full load. That’s two orders of magnitude less. Again, that’s with everything on at once. A realistic value is 4.16W. Not a big difference than all of them on, mostly due to the clearance and license plate LEDs taking most of the power in the first place. So, all the parking and operating lamps on the car illuminated for about half the power of a single incandescent clearance lamp. That’s a huge improvement:

4.92 W / 279W = 1.76% of the power with everything on, 4% with just the parking lights.

The catch? LEDs are expensive. Most of the cost is with the 1156 and 1157 replacements, at $20-30 per bulb. Also, digital flasher units are required rather than the heated element type in use (this also has a significant power drop, not calculated here). The total comes out to around $250. Ouch. Cheaper LEDs can be had, but they will not be as bright, and won’t last as long as quality units.

Continued here.