Our Kit Car Page2

GTM Libra History year 2000 to current date (sidewinderforge.co.uk)

sample image

Fuel Gauge, Tank Info'  & instrument panel info'

If you have Libra/Spyder fuel gauge problems then the following may be of interest:-
The fuel tank used is from a Rover Metro  & the following information  is  from  a popular car  maintenance handbook for the fuel tank/gauge sender unit.
FULL TANK     of fuel resistance should read   15.5 ohms
HALF TANK    of fuel resistance should read    65   ohms
EMPTY TANK            resistance  should  read  270 ohms

We did not use Rover Metro instrument panel voltage regulator for the instruments.
15/09/2017:- Correction - When we built our Libra we did not use the Rover or GTM fuel gauge, instead we used one from an American Classic Instruments Catalogue. In order to get the gauge to operate with the Rover fuel tank sender unit we had to put an 18 ohm resistor in series with the gauge and a 1.2 kohm in parallel with the tank sender. In the drawing to the right the 1.2 kohm resistor across the fuel gauge should be omitted.

The chosen instrument now gets :-
Full tank=33.3 ohm (requires 33 ohms).
Half tank = 83 ohms (requires 85 ohms)
Empty tank = 238.4 ohm (requires 240 ohms) 

We only discovered our mistake when the tank sender unit went faulty (poor ngative connection).. We also discovered that the 1.2 kohm resistor had been incorrectly placed from +12 battery to battery negative, thus serving no purpose. 

Here are a few tips -
1. Wiring colours - BL / W means a Blue cable with a thinner White tracer colour.
2.                          W / BL means a White cable with a thinner Blue tracer colour.

The Libra fuel pump feed, which has to have the new loom & the old loom, joined under the left hand side of the Dash is a  (W / Gn) White wire with a Green tracer colour.
Beware as there is also a (Gn / W) Green wire with a white tracer colour which goes to the Right Hand rear indicator light.

Our car would not energise the fuel pump when we did our first switch on. We had not got the indicator lights in place so we did not realise we were operating the indicators, unless you have the instruments fitted when the RH indicator warning lamp should light.

Back to top of page


Photo Gallery

Back to top of page