Speedometers

[sweet911]

I got a really great gift this past Christmas - my dream car!! - an '83 Porsche 911. I was searching for about 3 years and finally found something close to what I wanted. The car is sweet and have been pinching myself everytime I go into the garage - it's killing me not to drive it because of the snow - gotta love Canada!!! When not in the garage I'm surfing this site trying to get more information and learning things that I never really knew. Now my question....when I purchased the car the owner made me aware of 2 problems. When he redid the faceplates of the guages he said that the speedometer stopped working. I think the wiring got screwed up so I have ordered a speedocensor. Does anyone have a picture of the back of their speedometer that I can go by so that I check the wiring or can anyone direct me to someone that I can talk to as well about this? The other problem is that the roof won't close properly (Cabriolet). It was just redone and requires 2 people to close it. Is there some sort of adjustment that I am not aware of that would allow the roof to come forward more? Thanks in advance. P.S. Waiting 'til spring to send in my photo.

[asphaltgambler]

The wiring is DIN standard. Look at the where the male terminals are located on back of your speedo. Next to each one should be a number. The number indicates what circuit / wire color is supposed to be attached.

You should be able to google the DIN wiring standard for the decoding/wire color.

[Early_S_Man]

Pelican has a schematic in the Electrical Diagrams section of the site, and the relevant one is displayed below.

There may be someone with an SC that can post a pic, but there are a couple of checks you can make before that happens. You will need a multimeter ... either analog or digital will work.

1. Push the speedometer out from behind with one hand ... sometimes it helps to push out clock first.

2. Check for presence of +12 Volts at the terminal labeled [stamped] +12 V ... with the ignition switch turned on. The supply wire is Red/Black.

3. With ignition switch off ... check for continuity to a good chassis ground from the terminal labeled '-' ... there will be multiple wires on that terminal, probably three.

3. The wires from the speedo sensor are both Brown/Red ... it doesn't matter which is connected to terminal 31b and which is connected to the ground['-'] terminal.

4. With the back end of the car up on jack stands ... you should be able to see exactly eight contact closures [continuity with multimeter set to low Ohms scale] at the Brown/Red wires ... for exactly one revolution of the rear passenger tire/wheel. Alternatively, a 12 Volt test lamp should blink eight times when connected to +12 Volts and Terminal 31b ... when the rear wheel is rotated one revolution! The test is indicative of the health of the sensor and correct wiring connections.

[K. Roman]

1980 911SC, hope this helps.

[sweet911]

Thanks this is exactly what I was looking for. this forum is great and the people on it are even better. THANKS AGAIN Regards Joe

[3.2 CAB]

On the top being hard to close, is it still the 2 piece style that came on the early cars, or has it been changed or altered? If it is still factory specs, this might sound dumb, but are you un-ziping the rear window half before you are trying to close the top? If not, the big zipper needs to be opened to give the top the room to be closed, then once up and in the locked position, then you zip it closed. Also you unzip to open, leave it unzipped while folded, close top, then close zipper. If you are doing it that way and it still takes 2 people to close it, something is out of adjustment, or worse. I replaced my top 3yrs ago now, still looks great, but I don't think I would do it again though, it almost drove me insane what a major PITA. Good luck.