fuel gauge not working

[Dmaxx85]

Went out sat on my 1990 glatron 19.5' the gas gauge is jumping all over and not really working or even close to being accurate. I have an access hole in my floor that goes to what I believe is a sending unit for the fuel gauge???? One wire! What can I do to test this????

 

[produceguy]

Re: fuel gauge not working

You should have a pos and a neg going to your unit.
My geuss is that your neg is not grounded since it seems you have power to it.

 

[Silvertip]

Re: fuel gauge not working

Sending units are nothing more than a varible resistor in the range 240 ohms (empty) to 33 ohms (full). You say the gauge does not work, then it works but not accurate, etc. Fuel gauges by their very nature are not accurate because the senders themselves are cheaply made and subject to bouncing meter readings since there is a float on the end of a swing arm that rises and falls with the sloshing of fuel. Here is a diagram of the system - again.