International Lancia Forums

Original Veglia 67 1550 unit in std S1 fuel tank:

Ignition on, Gauge reads either max or min depending on fuel level with nothing in between.

Internal light works fine with car's lighting.

Taking unit out of the tank with wires attached get no reading unless I contact the body to the tank ring with same results by moving float arm.

Seems the case is earthed by bolts to make circuit as normally there is a cork seal.

Have changed gauge over to VDO and recently acquired a brand new VDO sender unit.

Connecting to same 2 wires i get no reading at all with new unit and existing VDO gauge.

Any ideas?

The ground connection comes through the body / tank and the M6 bolts.

The two wires are for the warning light and the gauge.
The yellow / black wire should be connected to terminal W and the black wire to terminal T

Since your gauge appears to be an on / off thing like the warning light, I suspect the wires have been swapped.

I suspect Huib is correct. I have been playing with this exact same problem with mine just yesterday. I had no reading as the sender unit mechanism was rusted, hence stuck in the lowest position. Freeing it off I connected the wires AAF and got the same symptoms you describe. Connecting them the correct way had it working perfectly !

Two differents senders :

http://img246.imageshack.us/img246/585/ful01cz3.jpg

left from 71' Fulvia 1600 HF

right from 73' Fulvia 3 1.3 S

My 1973 Fulvia 2 (1.3S) has the same sender as the 1971 HF you have illustrated, I assume the senders evolved over many years and not specific by model type.

Thanks for the tips.

Turns out that VDO doesn't allow you to reverse the polarity of the sender/gauge hence issues I was having!

By earthing the sender seperately from the gauge it now works. Kept the original Fuel tank hole and M4 x 6 tappings and had new gaskets made locally to suit the 60mm dia VDO sender.

So nice to have a reliable indication at last!