The fuel gauge in my 1981 240D hasn't been working in years. It always reads empty and the warning light stays on. Recently I removed the fuel tank gauge sending unit and took it apart and cleaned it. I noticed that one of the small copper wires inside had become disconnected on one end. Is is possible to repair it? I looked up buying a new one and they are close to 300.00!





"Installation is opposite of removal"

I have read where a member soldered the wire back together with good results.

If you need to replace the sender unit. The 80 - 82 240D uses a 17 gallon tank.
The 300D uses a 21 gallon tank.
Iam not sure if the length is different or if the width of the tank is different.

here is a quick search I did.

https://www.google.com/search?q=site+peachparts,+soldering+an+w123+fuel+sender&biw=1093&bih=521&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiLlcu7z_PLAhUFkIMKHfJ5Bo4Q_AUIBygC&dpr=1.25

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

One wire is a resistance wire, one is a contact. (One of those loops, i think the resistor wire). In my case the contact (for low fuel level) was broken. I replaced it with some very thin solid core wire.
Make sure your resistance wire is correctly making contact with the contacts on the floats. Its been a while, but I remember that there were a few ways of assembling it, and only one would force the wire into solid contact.

Soldering the wire back is totally possible, if you cant get the old solder to re melt, try melting a little fresh stuff in, that usually helps to make enough contact to transfer heat well enough to melt it

All 123 sedans use the same sender. Gas,300D and 240D.
I have a few tanks sitting around if you can't fix it.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

If the break isn't along a section where the float contacts have to pass, then it can be soldered. I've done this successfully where the break was at the very bottom. If this is the case, use a short length of copper wire to bridge the break. However, working with those wires is a delicate task. Try your best, but be prepared to install a replacement sender.