another stupid newbie question: what does this light mean? - PeachParts Mercedes-Benz Forum

niki716 · #1 05-05-2007, 10:05 AM

The glow plug light came on (the yellow coiled spring light) while I was driving, and I thought--this cannot be good

. As predicted in this forum, my charging system is not working--maybe I just need a new battery?

Anyway, I've been trying to get an owner's manual--they are not available at mbusa (possibly the hardest to navigate website in the world), and my

local Autozone had a Chilton's, but not the recoomended Haynes manual.

What's the light mean?

Matt L · #2 05-05-2007, 10:12 AM

The glow-plug indicator coming on while driving means that there is a fault in the system. Probably the relay is bad.

The service manual is available on CD or DVD from M-B.

sokoloff · #3 05-05-2007, 10:17 AM

Before throwing parts at the problem, test the glow plugs with an ohm meter to see if any of them are bad. Good ones will read 0.6 ohms cold. I'll take Matt's bet and bet on the glow plugs instead.

The charging system not working has nothing to do with that light in general. Are you talking about another problem too? If the battery is more than five years old, I'd just replace it.

BTW, I've got a brand new Haynes manual for the Mercedes diesels 1976 to 1985 available. Contact me off list if interested.

len@sokoloff.com

Johnhef · #4 05-05-2007, 01:23 PM

Had an afterthought since this morning- check the ground strap to the chassis and even possibly the block ground strap for corrosion. first things first, get that battery tested, then check charging voltage with your meter -or- have a shop run an alternator test.

toomany MBZ · #5 05-05-2007, 02:50 PM

Sounds like a loose connection somewhere. The seatbelt light in my CD comes on sometimes when I go over a bump...annoying, yet I think it's just a contact problem. Might be a similar deal, in that the light comes on, instead of the GP's themselves.

niki716 · #6 05-05-2007, 03:08 PM

Thanks for the suggestions. Cleaned off the corrosion from the battery and had it charged and tested at autozone (they say it's good). ground wire to the body from the barrty is solid and uncorroded. Car started up fine, no lights, but I didn't drive it anywhere, so...

For those who missed my earlier question, the glow plug light is new--the batter light had started to come on while driving, and the battery eventually went dead. After the third trip (each started with a jumper boost), the glow plug light came on, and there was no fourth trip--no boost would turn the car over until the trip to Autozone.

Now I'm afraid I'll get stranded.

btw, spoke to the mechanic who maintained the car before I bought it, and he said the glow plugs were replaced within the past year..they're good for a few years, right? I'll do the test anyway (although it means buying another tool, I'm guessing--and not one I can tile floors with, aaargh!).

Fortunately, this minor crisis allowed me to discover a neighbor who is handy, and also see another 300d in the area

--I'll find out if s/he's on the forum.

ImBroke · #7 05-05-2007, 04:13 PM

See,, this is what we were warning you about.. once you get started,, you''ll get hooked like a catfish on stinkbait. A little tweak here, tweak there, a few parts replacements etc....... Next thing you know you have three of them in your driveway.... It's quite the addiction.

Shorebilly · #8 05-06-2007, 05:43 AM

Quote:

Originally Posted by toomany MBZ

Sounds like a loose connection somewhere. The seatbelt light in my CD comes on sometimes when I go over a bump...annoying, yet I think it's just a contact problem. Might be a similar deal, in that the light comes on, instead of the GP's themselves.

Back in the day (before retirement), I was Chief Engineer aboard an old German built container ship......the Germans tend to use a lot of timers within their electrical control stuff......and I found that over time the magnet coils that hold the contacts in would get weak and cause them to drop out when they are bumped or jarred......

I get the interior light....the one that comes on when you open the front doors.....illuminating when I hit a bump just right......light comes on, times out and goes off.....I think the problem is in the timing relay.....will fix it someday when I am under the dash......I just hate laying on my back, all cramped up and working under there without an assistant to bring me stuff that I forgot to put someplace handy that I can reach.....and wearing glasses does not help a whole lot either.....getting old, and crotchety I guess.....

SB