Hi all, having an issue with my fuel gauge sender and gauge compatability on my indy build.

I have got a Ford ST Focus combined fuel pump and sender combination installed in my tank.
The sender is 200 ohm empty and 8 ohm full.

The telemetrix gauge I have requires a sender that is 10 ohms empty and 180 ohms full opposite to my Ford sender!

I have just found out from Caerbont that the Telemetrix gauges are not the standard heated bimetallic strip based on current flow but
they are whats known as a Air Core gauge which makes a direct measuement of the resistance of the sender.

Because my pump and sender are integral and already installed in my tank I really dont want to change these.

Has anyone come across the issue before and more importantly found a good solution?

The only option I can think of is to remove the pump and sensor and see if I can bend the float in such a way that it works in the opposite direction but I have already put the boot and rear panel in arrrghh!!

Any help would be appreciated.

Chris

These guys - https://www.spiyda.com/magento/index.php/vehicle-electronics/fuel-gauge-electronics/fuel-gauge-wizard-mk2.html will sell you a thingy which, they claim, will sort out mismatched gauges.

I haven't tried it yet as, although my gauge reads in reverse I know what it means

the usual trick is to bend the float arm 180°

not ideal for you, but its simple and it works



[Edited on 8/1/2014 by mcerd1]

I have a fuel gauge wizard to match gauge and sender it works very well, bit pricy but better than changing out sender etc..

On an old Sierra sender I I soldered the wire on the reostat and soldered to the other end
Although the range was still not as required by he gauge, it did now read the correct way round although never reads completely empty when it is

Thanks for the replies.

Yes mcerd1 spot on.

I bit the bullet and stripped pump out of tank today - not that bad a strip down after all and bent the arm accordingly.

Its going to read full until about half way down the tank but at least the last half of the tank will be measured correctly, I could have extended the arm but didn't see the need.

It has also put my mind to rest now I know how the telemetrix gauges work. I had assumed that current would be passed through the sender, to measure the resistance, which didn't feel right as it spends its life submerged in fuel! The telemetrix sender measures the actual resistance without passing a current through the sender as I understand (Air core movement)

So not wishing to alarm anyone, but if anyone is using a similar pump/sender combination like mine I guess it may not be wise to use an 'older' type smiths gauge which passes a current through the sender via a voltage regulator which is not how the original Ford Focus set up is.

Before and after pics - sender now reading the other way around.

Before


Sender 1

After 1


After 1

After 2


After 2

Chris

[Edited on 8/1/14 by chrisspartan]