1984 Speedometer quit!

[motorcop]

OK, so I have a 1984 911 cabrio. The odometer was not working but the speedometer was. I bought a used speedometer from a reputable dismantler and proceeded to switch it over. After installing the replacement taking it for a ride I have no speedo or odometer. So, I switch back to my original to see if the replacement was bad. Nothing, now I have no speedo or odometer on my original!! What the hell did I do??

[Racerbvd]

Make sure you got the plugs right, sounds like you switched em (I did that after I had mine rebuilt)

Good luck.

[motorcop]

Thanks Byron, I wondered about that. Any chance that you can give me a run down on the wiring colors to the connectors on the speedo so that I can check them?

[motorcop]

Im strongly thinking that I did somehow get my wires crossed while switching out the speedometer. (84 cab) Never answer the phone and have a 10 minute conversation while dealing with wires!! Can anyone help me out and tell me what goes where? One connector has 3 wires to it, another is white with a red tracer, etc...lights are a no brainer. Any help is greatly appreciated. Thanks

[rick-l]

Since you didn't get a response I can tell you what the Bentley says for an 84 but I have found it to be sketchy in certain areas.

There are two black/blue trace wires that go to illumination, I think those are in bulb sockets?
A white/green trace wire, the parking light indicator also in a socket?

White/red that goes t a terminal marked "A". It goes to the blower relay in the engine compartment in the back.

Red/black that is hot when the key is on, goes to the terminal marked "+".

Now is where it gets confusing. The remaining two terminals each have two wires attached. One terminal has two brown/red wires attached to it and the other a brown/red and a brown. There is nothing on the diagram to differentiate the terminals.

The only thing I could think of doing is that it shows the brown/red and a brown terminal to also be the ground for the lights so you could find that with a meter if the cartoon is correct.

it shows two brown/red wires going to the reed switch in the speed sensor. It does not matter which way these are attached but it does for the ground connection to the speedometer.

Your best bet would be if someone who did this recently would chime in so here is your morning bump

[Racerbvd]

Originally Posted by motorcop

Thanks Byron, I wondered about that. Any chance that you can give me a run down on the wiring colors to the connectors on the speedo so that I can check them?

I'll try and find a schematic, but must be at the shop in deland. I just reversed a the 2 longest wires & it worked.

[Mitch Leland]

I'm wondering if you've mixed up the wires you might have grounded the hot leads, if so I would check out your fuses if you already haven't done so...

[Bill in OKC]

I have a drawing I made before disconnecting my speedometer. I am not good with drawings on the internet but I'll try and describe the drawing as best I can. I don't have a pic - hope this might help.

the wires clockwise from left side
1. White/Green
2. Black/Blue (?bulb I think)
3. from bundle 1 red/black

4. blank position

5. from bundle 1 white/red

6. from bundle 1 top(outside most) - brown/red
(not from bundle) middle black/brown
(not from bundle) bottom (closest to center of gauge) brown/red

7. top (outside most) a double brown wire pair
middle from bundle 1 brown/red
bottom (closest to center of gauge) brown

8. black/blue (?bulb I think)

[motorcop]

Thanks to all, I found the wires I mixed up. All ok now.