Speedometer HELP!

[86 911]

I have a '76 911 with the 1976 wiring to the speedometer (150 MPH VDO gauge) and I'm encountering a problem. The speedometer isn't working at all, and is just dead and the needle isn't moving! I've checked the hot (red) wire, and it has 12 volts. The other wires are on tight and look to be very good. Here's what happened previously to the problem:
1)Sometimes one of the wires would come loose causing the speedometer to not work. Fix: put wire back on contact.
2) *yesterday* the speedometer needle would work intermittantly and before I pulled over to disconnect the wires so that it wouldn't do any damage, the needle rapidly and randomly jumped up and down.
Now: Today I've found some bad connections and fixed them in 2 of the wires thinking that would solve the problem. I've reconnected everything, and the speedometer is still not responding at all! I'm pretty sure I've got everything connected correctly. What could be causing the speedometer not to work? Could the sensor be bad due to the wires being loose?

Thanks

P.S. I've set up my wiring as shown in the photo in this thread: Speedometers

[86 911]

Problem Solved.

I've switched the hot wire with another doubled wire, and everything works. Apparently since the wiring in my car is a hack job, the wiring was really different from anything else.

[EdandQ]

Okay, it seems I have screwed up big time. In the process of fixing my speedo (it would not go past 50), and fixing the wipers at the same time, I have lost how the wiring goes on the speedo. I have read all the posts on this topic, but can't seem to find how mine works. In fact, my clock doesn't work now either! So, I'll start with the speedo.
I have three different connections available on the back of the speedo, not counting the lights.

It seems I have 3 available wires to go to these. I have one red, one brown, and a double brown (pass through)--- where do they bloomin' go?