Help with Water Level Sender

[PNM]

I have a VDO (1979) water level gauge and associated sender. The sender tests at 183.4 ohms with the tank full or empty.

Then sender has a 40/187 mark on the housing. Does this indicate 40-187 ohms, empty to full???

The sender has two wires.

The gauge appears to work normally. When I jumper across the two blade connectors - going to the sender - it goes to empty. The two wires from the sender also test 186 +/- ohms, at the gauge.

Am I missing something or do I have a bad sender and need to replace it with a sender with a range of approximately 40-190 ohms???

Thanks for your help.

[Wotname]

From the info you have posted - you have a bad sender.

The sender should read about 40 ohms when empty and about 187 ohms when full.