Problem with fuel level setup.

Post Reply
johnstevens
Posts: 1
Joined: Sun Sep 01, 2013 10:58 pm

Problem with fuel level setup.

Post by johnstevens »

I have encountered a strange problem while setting up the fuel system. I have a resistance fuel sender and have the 470 1/4-1/2 resistor installed. The system functions fine as long as the digital ohm meter is connected to the top of the fuel sender in the ohm mode. If I disconnect it or switch to voltage the numbers on the monitor go to the full setting of 20.5 The sender reads as follows. empty 244 ohm and 18.8 on aux1, full 34 ohm and 20.5 aux1. Initial start points are 0 and 100 per instruction. With the wires disconnected from the sender the read open 18.8 or closed 20.7. Is the problem in the sender? It ohm checks good on the bench. This is a new install with a model 2000 advanced.
Bobturner
Posts: 444
Joined: Mon Mar 11, 2013 6:34 pm

Re: Problem with fuel level setup.

Post by Bobturner »

First, a caution. You normally should not have your multimeter on 'ohms' if the circuit is powered up.
Is the ground side of the sensor connected to a good airframe ground? Do not rely on the screws that hold it in place.
Otherwise:
What voltages do you read at the sender? With the sender arm at the full position it should be low, a fraction of a volt. With the sender arm in the empty position, you should see about 1.5 volts. If that is what you have, then the calibration is incorrect. If the voltage is always only a fraction of a volt (my guess) then the 470 ohm resistor is defective, or much larger, or has a bad connection to the regulated 5 volt output from the EIS. Double check the color code, purple-yellow-brown. With the sensor disconnected you should see 5 volts on the sensor wire.
Post Reply