replacing interior lights with LED bulbs

Pulled and measured the bulbs. If anyone else is interested:

-- Room light and spots use a "festoon" style cylinder bulb with contacts at both pointed ends, 31mm long x 10mm diam, 8 watts each. The site I ordered LED bulbs from calls this a "3022" bulb.

-- Door step lights are also festoon style but slightly smaller, 29mm long x 8mm diam, 3 watts each. Again "3022" seems like the closest fit.

-- Cargo light is type "912", wedge base, bare glass bulb with wire contacts wrapped around the wedge. 1.4" long by 0.6" diam, 13 watts.

I ordered some LED lamps from superbrightleds.com to try out. If the door step lights fit, they should be about the same brightness, but only 1/3 watt instead of 3 watts each. New dome light should be somewhat brighter than stock, but only 1 watt instead of 8. Cargo light, dimmer than stock, but less than 1 watt instead of 13.

I'll post results when I get the new bulbs.

:7:
-Jeff

Received the LED bulbs a couple days ago.

Here's a picture of the old filament bulbs (top from left: 8w dome light, 3w step light, 13w cargo light) and new LED bulbs (bottom):


The new bulbs are all specified as "warm white" CCT, 3100-3200K.

Eyeball results:

-- Dome light (with 4 large emitters) is slightly brighter than the old one. Also, it can be rotated to make it even brighter in the front or rear of the passenger compartment. I rotated ours to rear since we also have the spot/map lights up front.

-- The new step lights (with 4 small emitters) look about the same brightness, but they give a much better tint of light than the old bulbs, which were a sickly yellow. I like the new ones better.

-- The new cargo light surprised me. With less than 1w total power consumption I thought it would be dimmer than the old 13w bulb. Nope, looks about the same brightness. The old bulb probably wasted most of its light inside the housing. The new bulb's tint is better too.

Here's the head of the cargo-light bulb:


And the backside of the dome-light bulb, which has a little buck driver to give constant output from 8V-30V. (The other lights have simple dropping resistors for 12V only.)


Was it worth it for about $20 total? For me, definitely. The extra brightness and better tints are nice. Plus if someone doesn't close a door completely, now the interior lights won't kill the battery in 24 hours. It would take more like 10 days.

:7:
-Jeff

mountains said:

This is a brilliant (no pun intended) mod. Will the cargo light actually completely drain the battery? Is there was a voltage sensor that cuts off all accessories if it starts getting too low. ???

Click to expand...

If you have a voltage sensor with cutoff, you should be fine. But I don't have a voltage sensor/cutoff in my OB.

When I did the math on my OB's battery it worked out to 550 watt-hours (110RC / 60min * 12V * 25A). The interior bulbs will draw much less than 25A, so the RC should be much longer...but on the other hand the battery could be a few years old, or not fully charged. So let's call it even and assume 550wh is a fair estimate.

So if I left the tailgate open with the stock bulbs (13w cargo + 8w dome = 21w), it would be dead in about 26 hours. Easily dead in a weekend.

With the new bulbs (1w dome + <1w cargo = <2w), it would take about 12 DAYS to kill the battery. Weekend or week with lights on, no problem.

Plus the brightness and tints are better. My LED flashlights typically use "neutral" 4000-4500K emitters. These bulbs are supposedly "warm" 3100-3200K LEDs. If that's true, my old incandescent bulbs are like 1000K. The old cargo & step bulbs look dark yellow by comparison. New ones look great.

:7:
-Jeff

p.s. Before you replace bulbs, check whether your car dims them and think about whether that matters to you. My 2001 does not dim these interior lights; it just turns them on or off. The voltage modulation for dimming an incandescent bulb will not work for an LED bulb.