collins_dan wrote:So I have been through the archives and want to confirm my conclusion. My 1970 S4 the fuel gauge recently started to only show empty when engine off, full when engine on. I checked all connections and all are good. I suspect the voltage stabilizer needs to be replaced. My only question is that I have a five spade unit, my first spade connection is a white green wire, then next to it are the two green wires, number 3 spade has nothing, number for four has one green wire and number 5 has nothing. I don’t see a white green wire on the wiring diagram, I see green black. What gives? Please confirm that I should replace and what is the significance of white green vs green black. Does it just signify unfused instead of fused? Thanks, Dan
It is all laid out clearly and correctly by Stu two posts back from yours.
saying you have a 5 spade unit is not very clear. Regardless of how many spades and putting numbers to them, you must refer to the terminals B and I (and possibly E or a ground symbol if fitted).
Lotus wiring colours mean nothing.
The convention though is for White/Green to be used where there is a second fuel pump...(Green/White though is RH indicator lamps). Have you, per chance, a second fuel pump that a PO might have done the right thing using a G/W wire and used the spare spade on the stabilser for switched power...only a guess. If not, then it is anyone's guess what the wire is doing! You will have to trace it I fear!
The Green/Black you see on the diagram
should be fuel gauge to tank sender...
With ignition switch on, check for voltage out of any of the green wires that you have. One, maybe two, should show 12V (plus or minus half a volt) This or these wires should be on the 'B' of your new stabiliser (suggest you get a modern one instead of an original)
The green wires that do not show voltage should be on the 'I' terminal of the stabiliser - double check that these wires go to 'B' or + terminals of your fuel and water gauges.
The stabiliser
might have a terminal marked 'E' or with a ground symbol - this is to earth.
To answer your question as to what is fused or unfused - complicated. On early UK cars, simply assume everything is unfused except Green or for many switches, where Green is the major colour. Wiring has moved on a long way since those days! Motto is to be careful of every colour - test twice and connect once!