Author Topic: Fuel gauge/ sender problem  (Read 4972 times)

nahuston

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Fuel gauge/ sender problem
« on: October 13, 2014, 21:04:45 »
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

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Re: Fuel gauge/ sender problem
« Reply #1 on: October 14, 2014, 13:57:14 »
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

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Re: Fuel gauge/ sender problem
« Reply #2 on: October 14, 2014, 14:09:53 »
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

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Re: Fuel gauge/ sender problem
« Reply #3 on: October 14, 2014, 17:41:37 »
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

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Re: Fuel gauge/ sender problem
« Reply #4 on: October 14, 2014, 21:49:35 »
My understanding is that the tube-style sender and the float-style sender are not interchangeable.
Scott Allen
'67 250 SL (early)
Altadena, California

ja17

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Re: Fuel gauge/ sender problem
« Reply #5 on: October 25, 2014, 07:35:59 »
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. 
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

scoot

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Re: Fuel gauge/ sender problem
« Reply #6 on: October 25, 2014, 13:37:25 »
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? 
Scott Allen
'67 250 SL (early)
Altadena, California

ja17

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Re: Fuel gauge/ sender problem
« Reply #7 on: October 27, 2014, 04:26:18 »
I believe so Soot.  I'll see if I have some around to photograph.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback