inoperable gas gauge

[bob66542]

well, i tinkered w/ my problem again this weekend, dissasembled and cleaned the tank sender that was in the car, it appears to be good- but when i connect it to harness, and hold upside down,(float at top) it shows empty on gauge. when held as it go's in tank,(float at bottom) gauge shows 1/4 tank.went back and read old posts at this site, and found a post saying the early cars used a different tank sending unit then the later cars(my car is a oct 64 build euro car) is it possible i need the early sending unit? has anyone used a late cylindrical style sender in an early car? and if so, was any rewireing required? help! --bob

65 SL 230 4-sp. purchase 12-08-03

[n/a]

when the late style sender is used in the early cars, the gauge reads 1/4 full as a maximum and acts in reverse, it goes up to 1/4 when it is getting low on gas, from what I remember.  It is possible to swap the gauge unit in the dash to the later style, if you really want to use the later sender, it is far easier to get an early sender to use in the car, I got mine from k&k, others have it as well, I think it was around $150.

-Lewis

66 230 sl 113042-10-016238
67 saab sonett II #43 of 258
00 saab 9-3 viggen conv
02 saab 9-5 aero

[bob66542]

thanks for the info lewis. does this early sending unit have the same bolt pattern as late one? i ask because i know my tank has been changed.-bob

65 SL 230 4-sp. purchase 12-08-03

[Naj ✝︎]

Hi, Bob,
I tried the cylindrical sender unit in my '65 230sl and it worked just like yours. I was in no mood to remove the instrument cluster (again!!) so I retained the original swimmer float unit.
Yes, the holes in the tank are exactly the same.
Only drawback is the gage needle dances about as you go round corners etc. but otherwise quite accurate.
naj

65 230SL
68 280SL

[German Dude]

Bob,

I came across your post and thought: Wow, exactly the same problem I have. I have a new-style sender unit in a 64 car and the gauge shows exactly the same.

Did you finally get the problem solved? If so, how?
Did you combine new sender with old float as suggested by Naj?

Thanks,

Juergen

Juergen
64 230SL #2933, 4sp, signal red, white hard top
93 Citroen XM station wagon