Does anybody know of a source for a nos sending unit p#3621615 or p#4051004 all the aftermarket units have a linear resistance wound resistor and read totally incorrect except when the tank is full or empty but the factory unit uses a non linear resistor to give the correct gauge reading. mine finally failed after 44 years Thanks

The dealer here had (may still) have a parts locating service nationwide thru Chrysler. Ebay might be a source & you might google chrysler NOS parts (not sure what wording to use) or out an ad in here & FABO & a good used one might be a solution

i tried looking for him at dealer that i am helping get rid of his nos parts. we don't have anything so i had boss look and it did not show anyone having one. the guy on ebay(hiltopap) is the guy that bought our nos stuff and he is out of those numbers at this time. boss is going to make some calls this pm and let me know what is out there. will post as soon as i know.

Dad needed a unit for his 1970 Pontiac, those are very unusual units, made of unobtainium. We finally resorted to Bob's Speedometer Shop for a rebuild.

https://www.bobsspeedometer.com/1/120/index.asp

A bit spendy but when there's nothing else available...

Robert

Soak it in EvapoRust to clean it up. Then pop off the cover and see what it looks like inside. There is a little "tab" inside that rides on the resistor. It could be broken or just worn and not making contact any more. You might be able to fix it.

Check out Manicini Racing....
They carry some nice replacements for A-bodies.. Not NOS but good quality..

Just my $0.02...

I have a working used one sitting around someplace from when I went to a trunk-mounted cell... make me an offer