Fuel sending units

[Rxcape]

Another question for the forum guru's.....

Fuel sending units

Fellow boaters.... I have a 1975 Trojan FBMY with Chrysler 440's and I am getting very erratic fuel readings on the bridge. The fuel gauges are AC gauges and I have tested them by grounding out the sending unit terminal on the gauge and the gauge will read full, returns to empty when ground is removed. I have tested continuity and all pass the test. The 3 gauges(starboard, port and generator) all react the same. This leads me to believe that the erratic readings are due to failing or failed sending units. I have researched trying to find out what the ohm readings are for the sending units but have not found any results. Would any of you knowledgeable people here on the forum happen to know what the ohm readings are so I can test/replace the sending units? Two separate 180gallon main tanks and one 40gallon generator tank.

I have searched the forum and see many posts regarding the sending units however did not see anything regarding the ohm reading of the sending units. I think that I read someplace that the original main tank sending units were 30-120ohms. Can anyone confirm this?

Thank you in advance for any suggestions and help.

[prowlersfish]

From What I understand The Delco sending units have a unique range and there is no replacement available. Bob at Beacon marine is well verst in the AC Delco gauges Give him a call. His number is at the bottom of the page on this link.

You did say all 3 were acting up? If all are acting up at the same time check your grounds



https://www.trojanboats.net/trojan-boat ... nders.html

[Rxcape]

Thank you Prowlersfish...

Yes, all three are inaccurate to varying degrees. I have searched the grounds and all look good but I have not disconnected and cleaned the connections. Next on my to-do list. The sending units are putting out an ohm reading at the tank but does not seem accurate when manually sounding the corresponding tank.

Thanks again!