Fuel gauge ohm readings

I just installed a used fuel gauge in my 66 CJ5 with the original configuration (e on right) and checked the ohm readings with the unit in the dash with all connections in place. Below are the readings I made. Some were not exactly the same as the specs listed in "Jaffers" tech article (can't find the link now) but mine is a 66 and the figures he gave are for 72-76. Does anyone know if ohm readings for 66 would be different or is my "new to me" gauge faulty?

S (sender post) to Ground = 27 ohms (shouldn't this be higher 68-72?)
S to I (ignition post) = 21 ohms (ok should be 19-21)
S to A (jumper to Temp post) 21 (ok should be 19-21)
I to A = 0 (ok should be zero)
I to Ground = 14 (shouldn't this be 49-51?)
A to Ground = 11 (shouldn't this be 49-51?)

Eddy

 

Thanks for finding that one. Heres another site for a 65 and both seem to agree on what the spec should be. The deal is all 3 of my post to ground readings are lower ohms than spec. All the other post combinations give the correct ohms. Does that give a clue as to where the problem is?

http://home.comcast.net/~sday77/binky/repair_gauges.htm

 

the only info I could find has to do with voltage to the gauge regualtor:
on a 12 volt system, if it's 10 volts or below, the gauge readings will be low.
likewise for 6 volt system, below 5 volts will give low readings

Note: fuel and temp gauges are 5% meters, that is, they must be accurate within 5% of a specific ohm value

 

Ok now the fuel gauge is working and for the record, the questionable ohm readings I made on the gauge were all on the 3 posts to ground. However the gauge was in the cluster fully installed with all wiring in place and the spec readings given in the tech files are what you'd expect "on the bench". Its possible the resistance readings were different because it was fully wired.

The reason the gauge pegged to full when I switched it on was the fuel sender. But it was something I could fix. So here I share what I found.

The fuel sender read 0.8ohms when the tank was empty. It should read around 72. I found the lower limit tang, those little metal brackets that limit the travel of the float arm, was bent allowing the arm to drop down too far. When it moved this far, the lock that holds the swing arm in the sending unti touched the housing and made continuity. I moved the arm through it's normal motion and the ohm reading were in spec except when it travel beyond its lower limit. I reshaped the limit tab to prevent this and the sender worked fine. I added a ground wire for good measure and now everthing is fine.

Eddy