Sigma fuel gauge

[Dave connors]

I've had to get a replacement fuel gauge for my 2011 fuel gauge  as the original fell to pieces although it still worked, the new one reads a lot lower than the original one they look identical  apart from the suppliers number on the back, anyone now if the replacement is correct, old one is shown on the left.

[John Vine]

I can only guess it's to do with Caerbont's own calibration, maybe for different models or model-years.  Can anyone advise on the significance of the -69B and -75B suffixes?

What model/year is your car, and who supplied the gauge?

If no-one can help, I think your best bet would be to ask Caerbont themselves, quoting your two  numbers.

Do let us know what you find out!

JV

[John Vine]

Just a thought...

Looking at your photo, it looks as though your old gauge has cracked round the rim, just under the bezel.  That's exactly what happened to mine some years ago (probably due to over-tightening the clamp), and I succeeded in repairing it (with either Araldite or superglue, I think).

JV

[John Vine]

This was mine before the repair:

JV

[Garth]

Also repaired mine with 'superglue' ages ago! Still fine! Although going to change one day!!

[John Vine]

A little more info...

According to CC parts website, -69B is the 1/4-sweep with black dial and chunky (non-italic) logo (P/N 71250):

The previous version (1998-2000) looks to be -59B.

And -78B says R400, although the label says CSR.

I can't find -75B anywhere.

JV

 

[R300 FNL]

I went from a 2003 to 2020 fuel gauge and the calibration was different with both gauges so caerbont had to recalibrate the new one. Maybe worth giving them a call. 
I wanted to change the bezel out at it is scratched, has anyone tried to remove the bezel & glass? 

[Dave connors]

I've contacted caerbont so ill wait and see what they have to say

[Dave connors]

Had a reply from Caebont it might mean something to someone here

EFC1-1152-75B   needs a sender that is 109 ohms empty & 4 ohms full, this may be a Caterham special as we don’t list one for those values

 

EFC1-1152-69B needs a sender that is 240 ohms empty & 22 full, non linear end to end.

 

[John Vine]

Very speedy response from Caerbont! 

You now have your answer.

The sender resistances for -69B are in line with the Ford Sigma/Duratec fuel pump fitted up to around 2015.  On my 2008 R400D, these came out as 209 ohms Empty, 24 ohms Full.

A sender resistance of, say, 100 ohms on your old -69B gauge (about 1/2 full) would give a much lower reading (approaching empty) on your -75B replacement.

It looks as though your new gauge is the wrong one for your car.  Can you return it for a refund?  Who supplied it?  And rather than chase down the correct gauge, it would probably be simpler to repair the old one.

ETA: An alternative might be to send the -75B to Caerbont for recalibration.

JV