Fuel Tank Sending Unit

[Biarritz]

I'm looking to replace my sending unit in my T2's fuel tank because the original one hasnt been reliable.  Got a new genuine Mopar 4051663 replacement and thought I'd check resistance on the new unit before installing:

Empty = 94 ohm

1/4      = OPEN CIRCUIT

1/2      = OPEN CIRCUIT

3/4      = OPEN CIRCUIT

Full     = OPEN CIRCUIT

 

This surely doesnt sound right for a new unit.  I would expect the resistance to decrease as the lever was raised towards full position.

 

So with that experience using a Mopar part, the only other option looks like Spectra for their aftermarket one.  Anyone have any experience with the Spectra FG64A?  Or other suggestions for a sending unit?

 

Edited August 12, 2016 by Biarritz
Changed the word level to lever (see edit history)

[Hemi Dude]

17 hours ago, Biarritz said:

I'm looking to replace my sending unit in my T2's fuel tank because the original one hasnt been reliable.  Got a new genuine Mopar 4051663 replacement and thought I'd check resistance on the new unit before installing:

Empty = 94 ohm                I read 106.2  ohms

1/4      = OPEN CIRCUIT   I read 

1/2      = OPEN CIRCUIT   I read  .728  M ohms

3/4      = OPEN CIRCUIT   I read

Full     = OPEN CIRCUIT    I read .720 M ohms

 

This surely doesnt sound right for a new unit.  I would expect the resistance to decrease as the lever was raised towards full position.

 

So with that experience using a Mopar part, the only other option looks like Spectra for their aftermarket one.  Anyone have any experience with the Spectra FG64A?  Or other suggestions for a sending unit?

 

I had ordered one for a customer, a Spectra FG64A. (MADE IN CHINA) Just pulled it out of the box. I find that the rheostat sticks badly as you sweep the arm through the entire movement.

I don't like the Spectra FG64A!

I think I will attempt to purchase the MOPAR 4051663 unit. 

I suggest you return yours for a replacement Try testing it as I have specified in a later message.

Edited August 13, 2016 by Hemi Dude (see edit history)

[Biarritz]

Hemi, Thanks for the reply.  Our measurements are consistent for the Empty reading, but your resistance on the FG64A doesnt sound right either for 1/2 and full.   Do you have any readings from a known-good Mopar unit or know what the range should be?  

 

I thought it was supposed to be around 100ohms (Empty) and about 10 ohms (Full) and should be linear between.  I can't find any hard data on it though.

 

The rheostat on the mopar unit mechanically operates smoothly but is also cheap plastic (nothing is sealed very well at all).  After looking closely at these, I'm surprised they work reliably at all on functional units. 

 

Since we both got questionable resistance readings on new units, could the rheostat possibly need the gas to keep its contacts clean?   If true, I don;t know how to tell if you got a functional unit before you install it. 

 

 

[Hemi Dude]

12 hours ago, Biarritz said:

Hemi, Thanks for the reply.  Our measurements are consistent for the Empty reading, but your resistance on the FG64A doesnt sound right either for 1/2 and full.   Do you have any readings from a known-good Mopar unit or know what the range should be?  

 

I thought it was supposed to be around 100ohms (Empty) and about 10 ohms (Full) and should be linear between.  I can't find any hard data on it though. 

 

The rheostat on the mopar unit mechanically operates smoothly but is also cheap plastic (nothing is sealed very well at all).  After looking closely at these, I'm surprised they work reliably at all on functional units. I remember that the factory ones had a plastic cover. As you can see, this is all metal. Cheap looking metal that looks like it would rust easily.

 

Since we both got questionable resistance readings on new units, could the rheostat possibly need the gas to keep its contacts clean?   If true, I don;t know how to tell if you got a functional unit before you install it. In the past, when I tested a used one, it was a smooth constant change.  But I also do not have the specs.  I will look to see if I can come up with something.

 

 

I have sent you a PM. with picture.

Edited August 13, 2016 by Hemi Dude (see edit history)

[marty mopar]

4051663 = 4051851,4051866,4051662  all these part numbers are equivalent