I've been replacing the bulbs inside my W123 300TD. I replaced the two illumination bulbs in the cluster (also foil-taped the bulb chamber). Wow. Big difference. Then I started changing out the smaller bulbs in the cluster for the indicator lights. This was trickier as the bulbs are soldered into a little plastic socket that twists on to the circuit board and locks into place. I hand soldered LEDs from ledlights.com into these holders. I did not do the battery indicator light yet; it was a different size.

All the indicators are a little brighter now. The turn signal indicators are almost too bright! BLINK. BLINK. BLINK.

I also replaced the climate control lights with LEDs. Those bulb holders were cracked up from the heat. Next up, I want to retrofit an LED into the spider optic cable for the buttons above the climate control. I tried an LED but it was not side firing and so put very little light into the cables. After that, I'll look at the shifter and window buttons. Then they should all match. I don't like the mismatch of LED and incandescent.

As it is, the LEDs look great, especially with blue interior. I've got LEDs in the dome lights as well. I've started on exterior lights. It's an entertaining project. But the dash improvement is fantastic.

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83 300TD, 260,000 miles, aka "Dusty"
6 vehicles, 2 cup holders (both in the dump truck)