Fuel sender resistance

[Roamingriverkid]

I have a 228 Seafarer and both my fuel tanks do not read on the gauge. Most likely connection corrosion at the tanks. Once in a while one tank will read. I have checked connections and power voltage at the gauge and all is good there. My question is does someone know what the expected resistance range should be from the sender's. And if you do, which end of the range reads full and empty.

 

[wspitler]

For US senders, the range is typically 30 - 240 ohms. The lower number is usually the full level.

 

[seasick]

A voltage reading at the sender has no real meaning. You can measure resistance as mentioned. The lower 30 ohm number represents full in the US. In Europe it's the reverse.
OK, a quick test of the gauge and wiring is to unplug the sender signal wire ( usually pink) and touch it to a good ground. The gauge when powered should read full. Disconnect the pink wire completely and the gauge should read empty.
A few things to keep in mind: There is a switch at the helm that selects which sender is connected to the fuel gauge. Of course, you have to have that set to the tank you want to test the sender on.
The switch itself or its wiring could be bad. That can be tested at the back of the switch.
The connections at the sender could be bad/corroded. That ground wire which may connect to the tank, needs a ground connected to the tank for the sender to work. In any event, the tank itself should be grounded if metal.
It is possible that both senders are bad but if both stopped working at the same time (and did work previously) the problem is probably at the switch or between the switch and the gauge.

 

[Roamingriverkid]

A voltage reading at the sender has no real meaning. You can measure resistance as mentioned. The lower 30 ohm number represents full in the US. In Europe it's the reverse.
OK, a quick test of the gauge and wiring is to unplug the sender signal wire ( usually pink) and touch it to a good ground. The gauge when powered should read full. Disconnect the pink wire completely and the gauge should read empty.
A few things to keep in mind: There is a switch at the helm that selects which sender is connected to the fuel gauge. Of course, you have to have that set to the tank you want to test the sender on.
The switch itself or its wiring could be bad. That can be tested at the back of the switch.
The connections at the sender could be bad/corroded. That ground wire which may connect to the tank, needs a ground connected to the tank for the sender to work. In any event, the tank itself should be grounded if metal.
It is possible that both senders are bad but if both stopped working at the same time (and did work previously) the problem is probably at the switch or between the switch and the gauge.

 

[Roamingriverkid]

Thank you both for the info and advice. I will try the suggestions.

 

[Roamingriverkid]

Update - Both fuel tank gauges now working. Couple ptoblems found. Both connectors from sending units were corroded. So i cleaned them up and still no readings at the gauge. So i pulled the switch/breaker panel to check connections there. Everything was connected. But what I did find is that the wires to the switch did not match the Grady wiring diagram. My pink/white wire was at the middle terminal and not at the top terminal of the switch. Change those around and whala! Guess the last time i worked on it i messed up. Opps getting old sucks!