I just finished replacing the fuel sender on my 95E320. Symptoms were twitchy fuel gauge, getting progressively worse over the last 12 months. Got 141 kmiles on the clock.

A very straightforward DYI repair. Access is thru the trunk after removing the interior trim on the forward vertical trunk wall to expose the gas tank.

Unplug the connector, then unscrew the sender retaining nut. When you pull the sender out of the tank, do it slowly to allow the gas to drain out of the sender before removing it all the way from the gas tank.

Replace with new parts, the sender and (2) new O-ring seals, and torque to 40 N-m. I got the new sender for $45, so it's not worth it to me to clean the old one. Fixed the twitchy gauge as others have posted already

OK - here is the question - when I received the new sender and compared it the the old one, the original had a 5 kohm resistor soldered on the top of the sender assembly that is electrically connected directly across the variable sender resistor (about 70 ohms on Empty). I transferred this resistor to the new P/N.

SO WHAT DOES THIS RESISTOR DO? And why is it not installed on new senders?

A bit of a nerd question - any comments?

__________________
Tom Latos
2002 E320
1995 E320 Sold at 288kmiles

Sorry TomLatos,

Don't know about that resistor but this story could be of some interest to owners of older MB's.
My W124 300TDT's fuel sender was also fluctuating below 1/2.
I am always adding an additif to the fuel when filling it up for cleaning the injectors and to prevent (to mutch) smoke.
A few weeks ago I was pleasantly surprised : during a ride of about 800 miles, I found out that the fuel gauge was again working as a new one and I didn't touch it at all !
BTW the additif is Marly CT1...
That was my easiest repair...

Danny