The low fuel light is indeed under the speedometer, but the "module" that activates the light is under the console cover, in front of - and possibly between - the actual fuel gage and oil pressure gage. It's a small round black cylinder with three wires coming out (IIRC). It sends 'ground' to the light (in the dash) on 1969 models, and sends 12VDC to the light on '67-8 models (again, IIRC!) It appears to have a small socket similar to a mini-Maglite bulb socket, but supposedly nothing goes in the socket on '69's but some device DOES go in for the previous years mentioned. This is all "as the story goes", because I have not yet seen mine work (it had a "bulb" in the socket, which we removed...) Heartbeat City has a decent picture of the module, I think they were asking in the neighborhood of $60 for them.
And this great pic of the speedometer reminds me of my younger/dumber days...I had it up to "PH", once...
