Engine/Transmission (1994 - 1998) Fuel sending unit resistance

[Joe G.]

I'm trying to diagnose a fuel gauge problem. I made the repair to the sending unit. It is smooth and the meter does not show any funny business like it did. Even with the float at the top of it's travel I only get about a 7/8 full reading on the gauge. The gauge checks out according to the service manual tests. Does anyone know what the resistance readings should be on the sending unit at full and empty? Or where I can find out what these values are?

 

[Vaughn MacKenzie]

Did you check the wiring between sending unit and gauge?



I don't know what the resistance range is but at $45 or whatever it was I didn't think it was worth the effort to try and fix the sending unit. I get mine from www.mopar4less.com since their prices are the best I've found (ask for Internet Parts).



Vaughn

 

[Joe G.]

I'm trying to find out what is wrong before buying any parts. If the sending unit is bad I will buy a new one. If I can't find out what the resistance is supposed to be I will probably buy a new one, but I would like to avoid that if I can. It takes a few days to get parts here.

 

[PKemp]

Joe: I have a whole new unit I haven't installed yet (sending unit). I can measure the resistance readings for you if you like. They should be pretty consistant from unit to unit (this one came from dodge, regular stock type unit, not an after-market place). I don't know what they are supposed to be but I can tell you what they are on this unit... . if that would help... .

 

[Joe G.]

It sure would help. Right now I don't know if the sending unit is bad or not. It works, but the gauge is not correct. I may have a corroded connector somewhere that is causeing the problem. Wouldn't be the first time that happened.

 

[PKemp]

Okay. I'll check it out tonight and post the results in the morning for you. My internet is still not working at home since hurricane Katrina.

 

[PKemp]

Joe: The Ohm readings on a digital are:



1. Fully down (empty tank): 112. 5 ohms



2. Fully up (full tank): 3. 5 ohms



I did notice that the empty reading is very stable but the full reading can push the float above (beyond) the upper contact surface end on the rheostat making it eratic at the "very" top only.



Hope this helps you out... ... .

 

[Joe G.]

Thank you very much for that. Mine is a little over 12 ohms at full and 113 ohms at empty. My gauge may be a little off at full, but not too bad. I think the problem is somewhere else. I suspect that the connector on top of the tank assembly may have problems. I'll check that out today. I'm more concerned about the empty end of the scale. That info helps a lot.

 

[Joe G.]

It's fixed. The connector was not connecting reliably. I cleaned it and made a very slight twist to the two pins. That fixed the intermittant crazyness. It was still reading lower than I like so I bought a new sender. Will wonders never cease? They had it in stock. The list price is now $73. 25. I got it for $57. 60.