in disconnecting the wiring from the gauge, it seemed easier to pull out the whole bulb fitting to which two wires were connected. see the attached drawing. is the center male connection the positive connection to the sensor, e.g., oil pressure sensor? this is e.g., a red and white wire. is the other connection, a brown wire, to ground? trying to understand and worried about getting this all back together.

McMark Says: I resized this image. It was 1224 x 3024 pixels.

I think we need a bigger drawing!

IIRC, the red/white wire is straight hot & daisy chained to most of them. Ground on these cars is always brown. On a 2 pole bulb, I don't think it matters which wire goes where.

On a two terminal socket put the "hot" (non-brown) wire to the center and the brown to the outer. You didn't ask but all the blue wires are the hot to the illumination bulbs.

Almost all of the gauge bulbs have two non-brown wires.

It should work either way. If you wanna get kookey, pull out your wiring diagram and trace the circuits.

I may have heard wrong but is'nt there a bulb that when removed messes with the charging system or somthing quits working right. Needs the feedback of the bulb. ? Fact or fiction?? What was the real question of this thread the bulb's ground wire? The center pin is the hot.

The critical bulb is the green "GEN" bulb. It is connected to the alternator and is in series in the circuit going to the alternator windings. When that bulb is on, power is going TO the alternator (which is needed to make it have a magnetic field and start producing power when it is spinning). Once the motor starts, the alt puts out juice through the voltage regulator that is equal to the battery and the bulb goes out. Wrong bulb in that spot and there isn't enough magnetic field to make the magic happen.