Fuel gauge calibration

Sometimes, ethanol can build up on the fuel sender "card".
Running Techron additive in the tank can clean the ethanol off.

Home Skillet wrote:
Sometimes, ethanol can build up on the fuel sender "card".
Running Techron additive in the tank can clean the ethanol off.

Would you please define "fuel sender card" I've not heard of this item before. Also how would ethanol get in the diesel fuel of the OP's fuel tank?

Richard

RLS7201 wrote:

Home Skillet wrote:
Sometimes, ethanol can build up on the fuel sender "card".
Running Techron additive in the tank can clean the ethanol off.

Would you please define "fuel sender card" I've not heard of this item before. Also how would ethanol get in the diesel fuel of the OP's fuel tank?

Richard

Sorry. Didn't realize the OP had a diesel.

Fuel sender card is the resistor/circuit board that the float makes contact with.

What chassis is your coach built on? Freightliner has a Service Center in Gaffney that did a lot of work for us when we had diesel coaches.
Sounds like a sending unit going bad, but maybe(?) the electrical connections just need cleaning?

brianseay1, I had a similar problem on my Monaco....1/8, then 1/2. then totally out in right field!
My problem was a failing fuel sending unit AND a bad gauge.
First I called the fuel sender company and they emailed me a document to test my sender, proving my sender was bad.
I ordered a new sender and installed it, but my gauge still was not correct.
I went to an auto parts store and bought a cheap fuel gauge and borrowed a 12VDC car battery.
I opened the driver side fuel door and found the wires leading to the fuel sender attached to the diesel fuel tank.
I marked each of these wires and disconnected each and electrical taped all ends.
I then ran wires from the fuel sender to the new gauge and battery.
The battery was at my feet and the new gauge was on the fuel tank next to the fuel sender......this was basically a test bench.
I unscrewed the fuel sender from the tank and lifted the sender up out of the tank simulating less fuel in the tank.
This should show the fuel gauge moving towards empty.
The new gauge reflected this.
When I disconnected my "test bench" and returned the wire connections to the fuel sender, my gauge still did not show the value that was on the new, test gauge.
New gauge went into the dash, old gauge became a rifle target, and all is reflecting correctly now....1/8 is 1/8, 1/2 is 1/2, and full is full. I have many detailed photos of this test that I could email you....just send me a PM.

Try restarting the vehicle's system by disconnecting the battery for a few minutes and then reconnecting it. This may help reset the errors and return the gauge to normal operation. Check the wiring and sensors.

For years I always felt bad because everything on my old truck worked except the fuel gauge. Could make work, but not accurate
Then I heard about space shuttle mission delayed several times because "fuel sensors malfunction". With their budget, and only used few times, they still had fuel gauge problems? I'll just put in what I expect to use today, or fill it up and use my trip meter. If I loose track, carry old CB antenna for dipstick.