Fuel tank sender unit

[Leyland]

Continuing with my restoration I have recently fitted new petrol tank, and a NOS sender unit. Checking the electrics when I turn ignition on the fuel gauge reads full, yet there is no fuel in tank.
One thought the tank is bedded in a mastic to seal it to the bodywork. Could I not be getting a good earth connection.? The leac from the gauge to the sender is all ok. New wiring harness. Any thoughts please. Ty

[Declan_Burns]

Test it with a test wire from the sensor unit to earth. If that solves your problem connect it permanently.
Regards
Declan

[Leyland]

Thanks Declan.
Another thing that has come to mind is the type of sender unit. I understand that there are two types of sender. I have a gold face speedo and fuel gauge. I read somewhere that the sender unit changed when black faced speedo and gauge were introduced. Is that correct.
I think my sender unit is a later one. Fairly flat top with lucar connector. Could I have the wrong sender for the gauge?
Any help appreciated
Ty

[firedrake1942]

Yup two types of sender (three if , as I believe to be the case the MM had a very early one) roughly divided into Gold faced speedo / fuel gauge and black faced ones. Inevitably the former are more expensive.

https://www.morrisminor.org.uk/parts/26-fuel-system

[ManyMinors]

Yes, if your sender has a Lucar connector it IS for the later (black face) gauge. You'll have to obtain the correct sender (or use the black gauge along with a voltage stabiliser I suppose).