Fuel Gauge Repair

[imported_Skinny]

First off, thanks Arks and Dunaruna for your feedback on my earlier post - it had a typo in it - here's a more accurate and detailed posting.

I have a 1983 Renken and a 1985 Chris Craft. Both have the exact same name brand instruments on their dashboards. The only sign of a company name or trademark on these instruments is a white "T" on the bottom of the instrument faces. The instruments are black and the scales and markings are white and brown. There?s two sets of numbers on the side of the fuel gauge, 1198777 and 3044 under that.

Anyone know what company this is so I can look up the specs? What ohm range the fuel gauge operates?

Does the fuel gauge actually measure a voltage drop or resistance (i.e., ohms)?

THE PROBLEM: The Renken fuel gauge does not work. The resistance between ground and the sender of the tank is 15k . The voltage difference between ground and the sender is 10v, and the difference between the sender and the ignition hot lead is 3v.

I replaced the original ?T? fuel gauge with a 30-240 ohm teleflex (not sure if this is the correct replacement) but the teleflex gauge does not work either. The needle does not move (i.e., reads empty just like the old ?T? gauge did) even though there's plenty of gas in the tank.

Any help would be appreciated.

Thanks, Skinny

 

[Silvertip]

Re: Fuel Gauge Repair

Except for some of tIhe newer, more sophisticated fuel senders, nearly all of the older float arm style senders were 33-240 ohm senders. When measuring the sender resistance you need to disconnect the sender wire either at the gauge or at the sender. If you have an idea how much fuel is in the tank then the sender resistance will be 33 ohms = full, 105 ohms = 1/2 full, or 240 ohms = empty (give or take a little on all readings). If resistance readings are way off from this, then the sender is defective or it is not a standard sender. To test the gauge, simply go to radio shack and buy a 30 ohm resistor and a 100 ohm resistor. Connect one end to the "S" terminal on the gauge and other end to the ground terminal. Turn the key on and if the gauge reads correctly (1/2 for the 100 ohm and full for the 30 ohm resistor), you know you have a bad sender, bad wiring, or a non standard sender. If the gauge reads incorrectly, you have wiring issues or a gauge/sender compatibility issue.

 

[Bondo]

Re: Fuel Gauge Repair

First off, thanks Arks and Dunaruna for your feedback on my earlier post - it had a typo in it - here's a more accurate and detailed posting.

Ayuh,.... So,.. Why start another thread,.... Now you have redundant info spread between 2 threads...
If you have a Typo problem,... Just hit the edit button at the bottom of whichever post needs editing...

What happens when you Ground out the sending wire at the sending unit,..??
It should Peg the gauge to Full....
If it Doesn't,...
Provided the gauge is Powered,...
The wire between the sending unit,+ the gauge is compromised....

 

[Silvertip]

Re: Fuel Gauge Repair

And there are at least three or four more recent posts about fuel gauge issues that have been answered -- complete with wiring diagrams. SEARCH is a great tool.

 

[Sandcastle]

Re: Fuel Gauge Repair

Except for some of tIhe newer, more sophisticated fuel senders, nearly all of the older float arm style senders were 33-240 ohm senders. When measuring the sender resistance you need to disconnect the sender wire either at the gauge or at the sender. If you have an idea how much fuel is in the tank then the sender resistance will be 33 ohms = full, 105 ohms = 1/2 full, or 240 ohms = empty (give or take a little on all readings). If resistance readings are way off from this, then the sender is defective or it is not a standard sender. To test the gauge, simply go to radio shack and buy a 30 ohm resistor and a 100 ohm resistor. Connect one end to the "S" terminal on the gauge and other end to the ground terminal. Turn the key on and if the gauge reads correctly (1/2 for the 100 ohm and full for the 30 ohm resistor), you know you have a bad sender, bad wiring, or a non standard sender. If the gauge reads incorrectly, you have wiring issues or a gauge/sender compatibility issue.

I have a Teleflex sending unit and gauge. I installed the new gauge and the sending unit and checked to see that the gauge went from empty to full while it was outside of the tank. I then installed it and it seemed to work fine at least for 12 hours or so when it just went dead and provided no reading. I took it out and check the resistance across the two poles and got no reading at all. I returned this gauge to West Marine and got another sending unit. Again I checked to see that it was working and it showed the proper operation outside the tank and similar readings when installed in the tank. Again, after less than 12 hours the sending unit was dead again. It seems that somehow the circuit is burning out the sending unit. Help!! I have no idea what to look for to correct. Any ideas???

 

[seabob4]

Re: Fuel Gauge Repair

If 12V+ is applied to the sender termination on the gauge, that will kill the sender. Is there a possibility this could be happening? You also might want to check your grounds, both at the gauge and the sender. Make sure they are good and tight...

 

[Bondo]

Re: Fuel Gauge Repair

I have a Teleflex sending unit and gauge. I installed the new gauge and the sending unit and checked to see that the gauge went from empty to full while it was outside of the tank. I then installed it and it seemed to work fine at least for 12 hours or so when it just went dead and provided no reading. I took it out and check the resistance across the two poles and got no reading at all. I returned this gauge to West Marine and got another sending unit. Again I checked to see that it was working and it showed the proper operation outside the tank and similar readings when installed in the tank. Again, after less than 12 hours the sending unit was dead again. It seems that somehow the circuit is burning out the sending unit. Help!! I have no idea what to look for to correct. Any ideas???

November 12th, 2008, 06:30 PM

Ayuh,.... So why are you posting on a 2 year old thread, instead of starting your Own,..??