Is my sending unit bad?

[Timmayy]

Ok, So I went to go take my 65 Coronet 4 door out for a ride. Gas gauge is reading empty. I go put some gas in it and the needle didn't move. I got underneath and checked the ohms on the sending unit. It's reading around 88-90 ohms. Should I just buy a new sending unit? What's a good quality one to get if that's the answer? Thanks all.

 

[JDmac72chrgr]

Does RI have ethonol gas? Used sending unit with the poly float & it ate the float, literally, have the "metal" float now, will see how that works.

 

[toolmanmike]

Ok, So I went to go take my 65 Coronet 4 door out for a ride. Gas gauge is reading empty. I go put some gas in it and the needle didn't move. I got underneath and checked the ohms on the sending unit. It's reading around 88-90 ohms. Should I just buy a new sending unit? What's a good quality one to get if that's the answer? Thanks all.

Good and quality don't belong in the same sentence when it comes to sending units. All, yes all aftermarket sending units are inaccurate. Send yours to Wolf and Company to be rebuilt.

 

[Aron Gleason]

The correct sending unit would be 70-30 ohms

 

[kiwigtx]

I am willing to bet you have a hole in the float, and it is full of gas....hence it has sunk to the bottom of the tank.

 

[Jerry Hall]

 

[dadsbee]

I'd say your float sunk. Ohm reading isn't out of the rhelm if it's sitting on bottom. Ground out the sender wire while someone watches the gauge and make sure it goes full scale. The you know it's your sending unit... and I lay odds on a sunk float.

Normal scale is about 72 ohms empty and 10 full.

 

[Timmayy]

I was thinking it was the float also. Should I just replace the float and screen?

 

[dadsbee]

If that's the cause, YES, new float and clean the sock and check the rheostat range of the sending unit while you have it out. Repros are junk..

Rat Rod Al has a batch of floats for sale right now in his "garage sale" for $10

 

[Timmayy]

I'd say your float sunk. Ohm reading isn't out of the rhelm if it's sitting on bottom. Ground out the sender wire while someone watches the gauge and make sure it goes full scale. The you know it's your sending unit... and I lay odds on a sunk float.

Normal scale is about 72 ohms empty and 10 full.

I'll try that.

 

[wvmarv]

Ok, So I went to go take my 65 Coronet 4 door out for a ride. Gas gauge is reading empty. I go put some gas in it and the needle didn't move. I got underneath and checked the ohms on the sending unit. It's reading around 88-90 ohms. Should I just buy a new sending unit? What's a good quality one to get if that's the answer? Thanks all.

Here's is a good article showing how to diagnose Mopar gauges.
Diagnosing And Repairing Faulty Instrument Gauges
https://www.hotrod.com/articles/23241-instrument-gauges-repair/

 

[dadsbee]

What the fawk are you disagreeing with Jon...

 

[69a100]

What the fawk are you disagreeing with Jon...

Fat fingers! They need to separate those two!!!!

 

[dadsbee]

Fat fingers! They need to separate those two!!!!

 

[Jerry Hall]

What the fawk are you disagreeing with Jon...

30 ohms is going to be somewhere around a half tank on the gauge. 10 ohms to full 73 or more to empty. This is per the gauge calibration chart when clusters are restored.

 

[dadsbee]

30 ohms is going to be somewhere around a half tank on the gauge. 10 ohms to full 73 or more to empty. This is per the gauge calibration chart when clusters are restored.

Wasn't Jon that disagreed with that wrong information it was R413. Jon had fat fingers on mine and corrected the big red X... LOL

 

[Jerry Hall]

I have taken a old 66-67 fuel tank and cut it so that I can adjust the repro 66-67 sending units to work very close to the originals. I find that with the aid of a simple tubing bender I can make them look and sit in the tank just like the originals. If you have a decent quality reproduction sending unit the ohms are close to correct. If not they're junk.

 

[Aron Gleason]

The correct sending unit would be 70-30 ohms

Ok my bad. Its 70-10 ohms

 

[Timmayy]

I'm going to test the gauge by grounding the wire first. If that's OK then I will order a new float and sock and pull the tank.

 

[dadsbee]

Get someone to watch the gauge to sweep full scale and yell when it does so you can quickly disconnect.

If you have a 10 ohm resistor in your collection you can put it between the wire and ground and the gauge should sit right on full. If not the quick ground and check should suffice, but DO NOT leave it grounded or you'll wreck your gauge.