Another Scott-Needs-To-Know-What-This-Is Thread. With a pic.
 

Correct answer is worth an extra $1 towards your PPOT Xmas gift this year.

This is from my '68 wiring harness. No idea what it is or where it mounts. Only ID marks are "30/51" stamped into the base. Five tabs total, looks like all of them were used due to marks on each. Can't believe I'm actually putting the harness back together and planning on putting it back into the car this month! Crazy talk.

http://img.tapatalk.com/1862ec07-8224-36eb.jpg

Its a relay. To what? Two spades on right are the coil. The single far left is com and the other two would be either NO and NC

To test: measure resistance across the two right terminals, if its the coil and its not failed you will get a number,

test continuity across switch, the single left terminal and the two middle terminal: one should read continuity, the other not.
If you ID the coil and its good apply 12 volts, then measure continuity across switch terminals. They should reverses position, close to open etc.

the older 911s had some funky electrical stuff on them - they may have even had a vibrator that looks like a simple relay

then there is the R window heater relay if fitted

it had carbs IIRC, too early for MFI & a cold start valve on it

if we are going to start a betting pool on who will be the first person to win, I will bet on John Cramer

The 31 /50 is probably connection reference points. Check schmatics for connections 31 and 50.

Vibrator? Whaaaaa?

Although this car didn't have MFI to begin with, it will when I put the drivetrain back in a few weeks from now. I'll take a gander at my manual this evening and see if I can spot those connection points.

Thanks for the tech support!!

you've never heard of a Multi-stable Vibrator?

they have red hair

Looks like the voltage regulator in my 356 - but there are too many connections...

it is a Black Magic box, filled with special smoke from Stuttgart.... if you let the smoke out, you are SOL. Rumor has it that an original container of NOS Stuttgart Smoke sold for a near record price, just below what a similar container filled with Lucas Smoke sold for a few months prior.

From the looks of it, at some point it was filled with water!

Now you bring up the whole reconciling-a-carbureted-1968-911-harness-with-MFI debacle. Hadn't really even given it a thought, given that both 1968 and 1969 911s were built with the technological equivalent of sticks and stones.

Wayne be da man: http://www.pelicanparts.com/911/911_Parts/Electrical/911_electrical_1965.jpg
-30/others not listed at a quick glance, but traceable.
-51 is "resistor relay".

Give them a call. Might be a p/n hidden under the gunk.

then there is the R window heater relay if fitted
http://www.lovelv.info/d.jpghttp://www.lovelv.info/h.jpg