What year 940? Got a VIN handy?
There are a number of different versions, and the early ones with a low pressure lift pump are different to later versions with a low pressure lift pump, and different again from those with an in-tank main pump.
The very early 940 senders won't work with later fuel gauges and vice versa, without mods at the cluster.
Edited to add: part numbers
(3547210) is the original complete unit for YM 1991
3507499-6 is the complete unit for YM 1992 (and supersedes the above)
6842610-5 is the complete unit for YM 1993
9142046-3 is the complete unit for NA 94
9142048-9 is the complete unit for +T 94
9125545-5 is the complete unit for NA 95+ (with single pump system)
9180932-7 is the complete unit for +T 95+ (with single pump system)
upto 94 -
94+