i'm in the process of wiring up some stewart warner electric gages for fuel and oil pressure. wiring for both gages is identical + for power, - for ground, S for sending unit and 1 pair for illumination. i ran the + and - in parallel (made the connection to 1 gage and jumpered the other gage off these connections). i haven't put any power on the gages yet, but when i use a meter and check for continuity from the gage connection to the end of each wire i see this: from any point on either gage (+, - or S) i get continuity on all connections on the other gage. i'd expect continuity between the parallel connections (+ and -) but not on the S terminals as well. does something sound wrong or will things straighten out when i put 12v to the gages?

You're probably reading continuity through the internal circuitry of the guages. Think about it.... If you didn't have continuity through the + & - side of the guage, it'd be broken/bad....

The "S/sender" input gives you variable resistance, which via the internals of the guage gives you proportional needle movement.

The lamp connection is a straight +DC input, voltage (brightness) variable by the dash/headlight dimmer switch.

IMO you've got things right.