Originally Posted by
lumpydog
Not sure if it's the sender not sending enough current (even though it's pinned) or the gauge reading improperly.
Hmm...I thought we just addressed this in another thread very, very recently. Maybe it was someone else with the exact same problem or on a different forum, but...
The "sender" doesn't send anything. It's just a variable resistor which controls the amount of electrical flow from the voltage stabilizer, through the gauge and then through the "sender" then on to ground, based on the position of the float in the tank. The gauge just measures that electrical flow and displays the result in a way that means something to the driver.
Troubleshooting the sender is a simple matter of comparing the resistance of the sender to known ohm values for different fuel states using the chart I made, at the bottom of this page (I presume you have a negative-ground sender).
Was the ohm reading you took on the sender in line with the ohm reading you'd expect to get for the amount of fuel you had in the tank?
In order for the fuel GAUGE to read accurately, the input voltage to the circuit must be correct. Any inaccuracy of the input voltage will affect the reading, since the current flowing through the circuit is mathematically related to the input voltage and the resistance of the circuit.
Is the correct average voltage being supplied to the gauge by the voltage stabilizer?
--Mark
1973 SIII 109 RHD 2.5NA Diesel
0-54mph in just under 11.5 minutes
(9.7 minutes now that she's a 3-door).