Testing a fuel cell sending unit....

[blykins]

I have looked up the part number on VDO's site (it's a VDO sender of course) and it lists this sender as being a 10-180 ohm sender.

I'm thinking that if your 240-33 sender shows 240 ohm empty, then I should flip the float around to the other side on this one. I have a 70-10 gauge.......I guess I should be showing 70 ohms empty. Right now, the sender has a "float side" stamp on the bottom of the sender.....and it's on the right side....When you place it there, 0 would correspond to empty and the higher resistance values would correspond to a full condition.

[MOTORHEAD]

Blykins:
Easy to check: With the fuel sender wire in the car not connected to anything (open), turn on ignition and see which way the gauge moves. If it pegs to "full", it wants high resistance for full, low for empty, and vice-versa.