No Alternator light and no charge after I took the battery out
 

Yesterday I successfully replaced my front condensor fan on my '79 911SC. That works great. During that I removed the battery, after the work I put it back in and hooked it up. The car starts great, but there is no alternator light before I crank it, and the voltage over the battery shows 12VDC. I checked the light bulb but that is fine. I measured from each side of the bulb and I have 12V to an earth point. I didn't hook the battery up backwards, cleaned all the connectors, etc, etc... Kind of at a loss what happened because I never even opened the engine lid, and everything up front was gone through again. Ideas?

If the VR "relay" contacts, the slip ring brushes, or the rotor windings, are open the bulb will not light....

'79, miles...?

92k miles, I've had it for a month. Seems strange that any of those things would be failing while I work on the condensor fan/battery, but I guess anything is possible. Any way to test any of those things?

edit to add it's been converted to an internal VR.

some sort of modification by previous owner?.

Check the rotor winding resistance at the appropriate VR socket connection, and the voltage at that some point with the ignition on.

This assumes that you car still has the factory VR.

Oops..internal VR...did the light work before?

Yes, although it was flickering at times at idle this last week. I'm guessing I somehow fried something that was already ready to go by taking the battery off and putting it back on.

As an update, it turned out to be the alternator stator. Happy to be driving it again!