The outside of the lamp, the socket, is your (+) to the idiot light. This is true of the oil idiot lamp as well. That means that your ground (-) is the actual wire that plugs into the lamp. So:Jays60rag wrote:One last tidbit to amuse everyone.
Turn on the ignition (if I am correct, your gen light is not going on).
Ground the wire at the gen lamp with a piece of spare wire.
Lamp now on? Good, follow that wire back to the voltage regulator and make sure it is securely attached.
Lamp not on? Swap bulbs with a known good bulb.
Lamp still not on? Check for proper (+) at the shell/socket back of cluster. Sometimes VWs have a little black wire bridge between the oil light and gen light base plates (which you now know must be insulated from actual ground metal in the vicinity). If the gen mounting plate/socket is inadvertantly grounded, you would have no idiot light at ignition, AND the alternator would indeed work perfectly when the car is running.
Colin