740 L4-2.3L SOHC VIN 88 B230F (1985)
Fuel Gauge: Technical Service Bulletins
Fuel Gauge Circuit - Operation
Section:
Group: 38
No. 102
Date: November 1984
RE: Fuel Gauge Circuit Operation
This Bulletin Is Applicable To The U.S. And Canadian Markets, And Applies To All 760 And 740 Models
The fuel gauge on the dashboard is like an ammeter; it is connected in series to a sensor.
Cars equipped with an auxiliary tank (D24T) have two tanks containing sensors and are wired in series.
The current flowing through the sensors is measured and recorded on the gauge as an indication of the fuel remaining in the tank(s).
The main tank sensor has a resistance range of 36 ohms when full and 296 ohms when empty.
The auxiliary tank sensor has a resistance range of 1 ohm when full and 18 ohm when empty.
Therefore, when the tank(s) are empty, the resistance of the sensor(s) is high and the current flowing through the circuit is small The gauge will show
empty.
With a full tank(s), the resistance is low and current flow is high.
NOTE:
There is only one main tank sensor
TESTING
