Low Fuel Warning Light
 

The low fuel light on my '85 td never seems to come on. When I start the car the light will go on so I know the bulb is good. Also, when I shorted the wire at the tank the light on the dash lights up. I just never see it come on in normal use, no matter how low the tank gets. I once even drove around with a gallon of diesel in a can in the back to see if the light would go on if I ran the tank really low. After the gauge read into "reserve" and well below empty I couldn't take it anymore and filled it up, but the light never went on. My wife has run it out on hills (we live in S.F.) when she's parked on a steep hill with a very low tank and couldn't restart (I suspect the intake was high and dry) but even then no light. Do I have a bad sending unit? The actual gauge works fine. Any thoughts here would be appreciated.

Thanks

Same thing on my 83 300d light goes on w/key, but doesn't go on w/low fuel. Unless there is an easy fix I intend to live w/it. My fuel guage works, but I prefer using the trip odometer as an indicator of fuel quantity.
Gregg

on my 83 300SD it has come on at strange times. It would come on with my battery light when my alternator was going, and then it came on when my guage read 1/4 for no apparent reason at all. I filled it up and figured out i had 3 gallons left! I've since run it down to 2.5 or so left and the light never came on??? oh well,
R

Mine Works, but I only "tested" once
 

Got caught with no diesel station in sight.

I NEVER go more that 300-350 miles between fill-ups. My thought is keep the fuel fresh and turning over and never suck out the last of a tank. Whether gas or diesel, I have always thought that only bad things happen when the tank runs too low.

Forget the light, and manage the fuel by the trip odometer.

JCD

Both of my MB lights go on when starting the car. However, only one seems to function with low fuel. I did the same by putting a couple of gallons in trunk and trying to run it out. A stupid thing to try I know but with the hand pump, I thought I'd be ok. After driving forever, I too gave up and just fill er up. At least we know that the thing will run forever on the last few gallons.

Don

Mine is always back-lit. I noticed the guage to be non linear. It drops off fast and slows as I get towards1/4 tank. I have run it down to R and stil have 4-5 gals left.

I have the same problem on my 240d, the light is always on, and the gauge reads just under half, when it's empty.

Apparently the sending unit in the tank gets gummed up by algae and sends false readings. Pull the first aid kit housing to access the gauge thingy and try cleaning it...