300D domelight - PeachParts Mercedes-Benz Forum

BetseyBenz · #1 02-16-2006, 06:57 PM

So the domelight in my 300D (Betsey) hasn't worked since I got her 8 months ago. The rear reading light works from the switch on the dash and when the door is open (only the rear door?). I replaced the fuses when I got the car, but no go. So I got a new bulb, and still nothing on any setting.

What's a good way to check if there is power to the plug that goes into the fixture itself, before I go track down a replacement?

Thanks in advance.

Steve.

my123ca · #2 02-16-2006, 07:44 PM

The red wire(s) on that unit should have power all the time. Test if the red wire has power. Use the brown wire on that unit as ground. Since your rear dome light is working you can eliminate the fuse. They use the same fuse.

MTUpower · #3 02-16-2006, 07:50 PM

Your dome light does not have a switch to turn it on and off on the dash- only the light itself if it's a w123. Please post the year/chassis to help others solve your problem.

BetseyBenz · #4 02-16-2006, 07:59 PM

of course you need the year and model to give me any help--and I'll get it on my signature as well.

1984 300D Turbodiesel

You're right -- there is a switch on the dash for the light in the rear only, and a switch on the light fixture itself for the front dome light.

Steve.

ImBroke · #5 02-16-2006, 08:42 PM

A cheap digital multimeter will help you a lot. you don't need anything fancy, and remember, if you don't read any voltage the first time, check your ground.

BetseyBenz · #6 02-17-2006, 12:45 PM

Thanks all -- I'll give this a shot next week!

I don't have a multimeter, but I have a battery tester with a ground clip—that should show if there is current, right?

Biodiesel300TD · #7 02-17-2006, 01:20 PM

You might check the door switches too. Mine dome didn't work when the doors were open. I took the switched out and cleaned them up and they work fine now.

sailor15015 · #8 02-17-2006, 11:39 PM

My seatbelt warning buzzer was weak and extremely annoying so I unplugged it. Right after that I discovered that my front dome light would only come on when the passenger side door was open, not the driver's side door. I didn't make the connection for about two months. I plugged the silver box back in and back came my lights.