Fuel gauge/ sender problem

[nahuston]

I need some help tracking down a fuel gauge issue. When I turn the key on the gauge pegs full all the time. The low warning light still works. I assumed there was a short to ground somewhere in the harness but I have checked and there is not. I have swapped gauges and it still pegs (with the sender plugged in or unplugged). Does anyone know what resistance I should see on the wire to the gauge (blue green)? Is it expected that the gauge would peg full with the sender unplugged? I would expect it to drop to zero not full but maybe its different in these cars?
Thanks

[nahuston]

I found another 230sl and unplugged the sender - the gauge pegged full. Looks like a need a sender. I have the early style, in reading here it looks like I can't use the newer style "tube'? Is that correct?

[WRe]

Hi,
the early 230SL (until 1964/65) had an arm of lever sender, later than all the same tube; see http://www.sl113.org/wiki/Fuel/SenderUnit.
...WRe

[jf308]

MB Classic center just sold me a "tube style" for my 64 230 SL and that is war came out of the old tank.  Will let you know if it functions shortly.

John

[scoot]

My understanding is that the tube-style sender and the float-style sender are not interchangeable.

[ja17]

There are  early and late "tube style" I believe.  The lever type and early tube style are interchangeable.  The later tube style (most common) and the lever style are not unless the gauges are change also. I have taken both tube styles apart and one has three vertical wires and the other has two vertical wires. 

[scoot]

There are  early and late "tube style" I believe.  The lever type and early tube style are interchangeable.  The later tube style (most common) and the lever style are not unless the gauges are change also. I have taken both tube styles apart and one has three vertical wires and the other has two vertical wires. 

That is very interesting and something I have never heard before.  If you have pictures please post.  Would the early style tube sender correspond to an early Fintail also? 

[ja17]

I believe so Soot.  I'll see if I have some around to photograph.