This is probably a good JMartin or Jim Lane question. My fuel gauge worked once for a few seconds a couple years ago. It read about 1/2 tank. I siphoned about 16 gallons out when I dropped the tank so that seems accurate.
The float arm assembly was pretty loose so I pressed it to the other part of the sending unit with light finger pressure to ensure good conductivity. I was able to get variable Ohm readings from the top and middle wire tabs that were somewhat consistent. I got either no ohms or wildly fluctuating ohms from the middle tab and bottom tab. Ditto for the top and bottom tab.


Is there a better way to test this? What indicates a faulty unit? Thanks.

 

insulated wire connection on top is one connection, base connector is ground, cant remember exact resistance, but 0-65 ohms is close enough, you don't want fluxuation through sender travel, smooth resistance change for accurate gauge activity.

 

$62.00 plus shipping and you won't wonder anymore....



https://www.genosgarage.com/product/...lacement-parts

It's been discontinued by Mopar, but Geno's has a few of them.

I'm sure J knows how to test it, and eventually he'll chime in.



BTW, I just bought one for a spare, and it cost me $73.90 with the shipping. When I get the new one, if you want, I'll check the OHMS readings for you, and see how you compare. I would just have to figure out "HOW" to do this.

 

Yeah I saw that Geno's had them. I found a new one on Ebay for $50 shipped. If mine proves to be good I'll keep it as a spare. Gotta love NLA...NOT!!!

 

That's about what I was getting for ohms. It seemed to be a pretty smooth increase/decrease with movement of the arm. Occasionally it would drop out. That could also be attributed to my lack of a third hand.

 

i had one that bench tested just fine, the moment i dropped it into a tank of fuel, no joy. the float arm was loose/sloppy so the little contact would break contact once it was free floating.

i bought an NOS unit off eBay, came in a sealed mopar box. been working great for about 9 months.

 

I bought an NOS unit from ebay last night. There are 2 posts i've read about fixing the arm slop. Here is a link to the one I'm going to do when I reinstall everything. Sort of a preemptive strike.

The write up is for a 2nd gen sender but ours is very similar if not identical. I found the bracket that they show on a 2nd gen gasser in the JY.

Fuel Sending Unit Repair For Under $1 - Dodge Cummins Diesel Forum

 

So if I have a fuel gauge that doesn't register on my 91. Would you guys recommend changing just the lever or the whole unit? If it's the whole unit where is the best place to get one? Thanks.