I bought a 2 1/16" VDO fuel gauge thinking I could hook it up to my stock sender...will this work?

Can I splice into the wire behind the current gauge and send to the add on gauge too?

Mine works just fine with the stock sender, but I think that VDO makes more than one fuel gauge.

One of the VDO cockpit gauges claims to work with the VW classic beetle sender, which is the same calibration as ours. You cannot connect more than one gauge to the sender, however.

ah so I can't really splice into the wire. I have to disconnect the stock on and connect to the add on.

With the gauge powered but but no sender wire (say the wire broke); will it read at zero or all the way up?

Does the ground from the sender make the needle go higher or lower? trying to see if the gauge even works...

It will depend on the gauge; some will read full, some empty when the sender is disconnected. Best bet is probably to ground the sender wire while the gauge is on and see if it moves...