Which Gauge Terminal to Sending Unit

[delta31]

Is there a way to tell which of the two terminals on the back of the gauges goes to the sending unit?
I see on the back of the gauges that one receptacle has bosses and one has slots, can you which one goes to the
sending unit and which goes toward the battery?

Thanks

[just me]

The one the spider doesn't connect to is the sender.

[PoW]

If your wiring harness is correct, you can't hook them up wrong.

i.e. It only fits one way.

PoW

[mike_l]

On my gauge, when mounted in the dash, the outer connector (further from the speedometer) with the slots is the sender unit side. The inner connector (closer to the speedometer) is the spider connector and has the nubs/tabs inside.

Or, if you have it in your hand, looking at the back, the connector on your left is the sender unit.

[vargaspj]

If you look up the MIL-STD's for those gages, the smooth connector goes to IGNITION and the ribbed connector goes to SENDER.

[vargaspj]

Ignition connection would be to the dash spider harness (+24 VDC hot when the ignition is on).