petrol and temp gauge wiring

[DickB]

good stuff. Pictures are helpful. I  don't appear to have a low fuel warning light but there are three wires coming from the sender, including the earth.

I will shorten the earth to start as it has been , for some reason, wired to the bulk head under the bonnet. I will do a shorter wire with good contacts ensured. I checked the gauge again and it definitely works.

Also found a really useful diagram on Paddock spares, which has the three spade terminals. I am guessing I don't require all three as the is no low fuel level gauge.

The fuel gauge does work but it can read too hot and also below the mid temp on the gauge i.e. pretty cool. Th engine runs well despite the temp readings either way.

[DickB]

looking again at your pic, this is the same with the three spade terminals. I am guessing the two with the white plastic bases are for low level fuel light and the gauge itself, via the voltage regulator? and the other spade is the earth?

And at the back of the petrol gauge itself, only has a single live wire attached to it coming from the VR? So the other spade is left unattached? Or should it be earthed also? I don't think it does, as when I have added a direct earth, it jumps to full!

[Wittsend]

There's no reason why petrol owners shouldn't wire up the low fuel warning light.

No "gauge" as such, just a simple 12V warning lamp - OE was Blue. You just need to drill an extra hole in the dash and wire up as per my diagram:-



Just one more light to worry about

The back of the fuel Gauge has 2 terminals.
One goes to the voltage stabiliser mark "I" (for instrument) There should be another wire to the temp gauge.

The 2nd terminal goes to the "T" on the tank sender - as per my diagram.
The fuel gauge itself is not earthed. The circuit is completed through the tank sender's earth.

The other terminal; on the water temp gauge goes to the terminal on the sender in the engine block - where that circuit is earthed through the engine block.

[Craig T]

The voltage stabiliser needs no earth. It grounds through the body and into the gauge. Don't add an earth to any of the spade connectors on that.

Craig.

[DickB]

I think I have sussed it out.


I have measured the resistance on the fuel sender, and if I am correct , it reads 145 ohms. So it suggests that the sender is stuck either full or empty. I am not entirely sure of the resistance values at either end of the scale.
And the voltage stabilizer also reads low on the "I" terminal, fluctuating between 7.9 and 8.1 volts. The B terminal reads 12.6 v, as the battery does with the engine static. I think this is how to measure (without the engine running?).

Just checked on line and it says zero ohms is full and 120 is empty. So , I guess mines very empty (except it isn't).


Can you do this with the engine running? The voltage test on the stabilizer I mean. I have tried and it blows a fuse.