OK, I think I'm on the last lap of this whole ordeal.

I've learned some key things:
1) My multimeter is junk. Why? It reads 0-1,000, not 0-100 and I thought. So the ~100 ohms between empty and full are not clearly registering on this stupid Radio-Shack POS. It cannot be adjusted for range!! I *am* now getting a reading, just a very small one (on the 0-1000 scale).

2) The wiring between the harness plug and the resistor coils is fine. After I cut them loose from the coils, I twisted the ends together and took a new OHM reading from back at the harness plug. I get a solid 0 Ohms reading, meaning this wiring is fine!

3) The nickel-plated metal tab on the float (the one that touches both resistor coils thereby creating a resistance value) It's fine! Nothing wrong with it.

4) after reassembling the float-canister, I took some ohm readings from the ends of the coils (not the wires) and I get a a solid 0 ohms at the full end (float at the top), and I get ~100 ohms (can't see excactly because of the cheap multimeter) at empty (float at the bottom).

Working Conclusion: The wires sodered at the top of the coils are not making a good connection!! I'm goimg to resoder the wiring to the coils shortly, recheck the ohms (if possible with a more sensitive multimeter), then test it on my car (using a bucket of water). I have high hopes that this might work.

However, daylight is almost gone, so I may not be able to get to the "field" test before tomorrow.


One fairly important question: can I use shrink tubing inside the tank (at the coils) to help seal the connection?


--
Volvo #6: all wagons.... 1972 145S, 1976 245 DL, 1983 245 GL, 1986 740 GLE, 1990 740 GL, now a 1995 940...