fuel sender, again again, againagain

[ferny]

Ok, since I've owned the car (2006) the fuel gauge has alweays read the reverse of what it should. Gauges and what-not have all been swapped around and it's always been the same. Even a new sender made no difference. Seeing as I'm starting with a known good gauge (the Mazda one) which operates on an unregulated 12v feed and I've got naff all fuel in the tank I thought I'd revisit the issue.

Looking at the photo below (in its empty position as sits in my tank) I think it's clear why it only read for the last 20 miles or so. To me the windings look fecked and too far spaced. Can anyone confirm? Bending the contact only makes it get caught on the bowed windings in the middle. Also, should it all be orientated in this way? I can play around bending arms and repositioning floats all I want and despite the insistence of someone else to do so I have as much desire to have a gauge which tells me when I've used 20 miles worth of fuel and then no warning of running out as I have to stick my doodad in a light socket.

It's also the sender with screws, not bayonet which according to Rimmer Bros is incorrect for a '68 car? Not exactly fussed about originality, just curious.

[Mark Hammond]

Could be either IIRC, '68 was changeover point with 13/60 coming out in late '67.  Wasn't '68 when the 13/60 started using the larger tank too?  Is yours a 1200 or 13/60 and is it a '68 build or a '68 registered car?

Mark

[piman]

Hello Ferny,

I have to agree with you, it does look very second hand.

Does your gauge read full when the sender wire is earthed? Looking at your picture, the left hand contact logically looks as though it is attached to the insulated strip which is where the sender wire would be connected and the other end of the resistance strip is earth. So when empty full resistance is sensed by the gauge and it should read empty?

I would say a replacement sender is needed?

Alec

[ferny]

1218 wrote:

Could be either IIRC, '68 was changeover point with 13/60 coming out in late '67.  Wasn't '68 when the 13/60 started using the larger tank too?  Is yours a 1200 or 13/60 and is it a '68 build or a '68 registered car?

Mark

It's a '68 13/60. First registered on 01/02/1968 but no idea on the build date. Although it's the second tank the car had had in my ownership it's always had the small tank, sadly. I'd love a bigger one and was even contemplating an alternative.

piman wrote:

Hello Ferny,

I have to agree with you, it does look very second hand.

Does your gauge read full when the sender wire is earthed? Looking at your picture, the left hand contact logically looks as though it is attached to the insulated strip which is where the sender wire would be connected and the other end of the resistance strip is earth. So when empty full resistance is sensed by the gauge and it should read empty?

I would say a replacement sender is needed?

Alec

Yep, the gauge works perfectly so the issues is certainly with the sender. I was wondering if it had been fiddled with in the past but without having two next to each other it's impossible to be fully sure, which is why I've thrown it up and asked the questions.

I'll keep an eye our to see what pops up second hand then but probably grab a new one down the line. For now I at least know I've got some miles before I run out. :)

[DougBGT6]

It looks in similar condition to my one on the GT6!   :-/ I think the windings have to be electrically intact to get any reading so you may be OK with that. The problem with mine was the aluminium case, aluminium is a conductor but, aluminium oxide is not.  Once I'd cleaned up the case and the float mechanism it worked. But it's a fiddly job that could go horribly wrong. I have no expectation it will last and I have it on my list to replace at some point.

As to reading backwards, what happens if you reverse the wires on the gauge?  ;D

[piman]

Hello Doug,

I can't see that would make any difference, that's why I asked if the gauge goes to full scale when the sender wire is earthed, if it doesn't then that sender is the wrong one. (Or more accurately, the gauge is wrong for the car.)

Alec

[Nick Moore]

Errm, without meaning to impugn your mechanickery skills Ferny, is it possible that the reason the gauge reads backwards is because you've installed the sender upside down?

I recently replaced my Herald's sender with a new one from Rimmers. That isn't a free plug for Rimmers though, as other suppliers no doubt stock the senders too. The new sender works very well, and is fairly accurate after a bit of arm twisting. The gasket supplied with the sender was fecking useless, but a new one cut from rubberised gasket material works perfectly.

[ferny]

It's not impossible, but it is unlikely. You have to tweak the float and the arm to be able to fit it upside down and it's not improbable that a previous owner has done that. But luckily the outside has "TOP" written on it. :)

After deciding on Wednesday that the Mazda sender wouldn't fit I got up today and had another think. Or rather, I took some resistance readings then ploughed on in ignorance. The two senders put out completely different figures (I've been firmly told the Triumph sender would be fine to use...). Also, the Triumph gauge was giving wild readings with resistance shooting up and down randomly along its scale. So this morning I have mostly been...










As for the gaskets - I've had success with chemical metals in the past. When I used last time was a metal based filler and it stood up for a few years and hadn't leaked.
http://www.henkel.co.uk/3185_UKE_HTML.htm?BU=industrial&parentredDotUID=productfinder&redDotUID=1000000JB9360645

[Pete Lewis]

pete i have a spare new sender for bi metal gauge ( slow needle) use.  the moving iron ( wavy) needle gauge sender works the oposite way round and thats what you seem to be fighting with, you cant intermix stablised and non stabilised systems

you can cut the holes off a 6 hole sender to make it fit in a later bayonet ring fitting but not the other way round

if you want a second one to play with pop  down.    

you need to match the sender to the type of gauge fitted , many places sell the later one only and say they are all the same
you can get 6 hole non stabilised and six hole stabilised , so they all fit but wont ever work if intermixed

Pete

[ferny]

Thanks, but it'd still give the incorrect readings if I use any Triumph sender.

All sorted now. It's set to read just beyond empty when I've got 4-5 litres of fuel in it, so I've kinda got a imitation warning light, if you will. And as the arm is slightly longer (had to be bent to shorten it and so it'd miss the side of the tank and the baffle) it'll read full for the first 3-4 litres of fuel used. But, I'll know when I've got half a tank and when I'm going to run out, which is important! And the fumes from melting plastic which has been sitting in petrol for 20+ years certainly gives the fifth cup of coffee an extra kick! ;)


Not pretty, but it works!