Fuel Gauge wiring

Post by **markattard** » Mon Feb 06, 2006 11:44 am

Could anyone pl advice on wiring the 948 fuel gauge, i need a diagram to show which terminal (of the two on the gauge) goes to the sender and obviously the other to the positive

tanx

Post by **Willie** » Mon Feb 06, 2006 8:02 pm

Interesting....the wiring diagrams give no indication that the terminals on the
actual fuel gauge are marked in any way! The gauge works on the thermal
principle NOT polarity so, as far as I can see,it makes no difference which
way round you connect the gauge provided that you have 3 Green wires on
one terminal and the Green/Black wire from the tank sender unit on the other. Perhaps someone else can confirm this?? In case you have done any
mods in that area it is essential to use the 948 tank sender unit with a 948
fuel gauge, you cannot use a later sender.

Post by **d_harris** » Tue Feb 07, 2006 3:30 am

Surely if you get the polarity wrong it would just indicate "empty" the whole time?

Post by **Willie** » Tue Feb 07, 2006 8:45 am

It would if the gauge was polarity conscious but it isn't! If you think that is
why the earlier type tank sender will not work with the 1098 fuel gauges is
not the reason. The senders are configured differently which means that
one type reads maximum resistance when full whereas the other type reads
exactly the opposite which makes the wrong sender/gauge combination read
backwards! I should also clarify that only on the cars WITHOUT a voltage
stabiliser do the three green wires go directly to the fuel gauge terminal. If
there is a stabiliser then the three green wires go to the terminal on that which is marked 'B' (battery) and the light green wire goes from terminal
marked 'I'(instrument) to the fuel gauge.

Post by **markattard** » Tue Feb 07, 2006 9:07 am

thanks to all.....