Speedometer/Odometer Wiring

[avale]

I have an '87 911 and after filling up, pressed the plunger to reset the trip odometer and quickly noticed that trip odometer was no longer working. Gas station is right by my house so only have like 2/10th of a mile that isn't registered on my odometer. I've read all the threads about repairing this myself, but I live a mile away from Palo Alto Speedometer - so that is my repair path. I took a picture of my speedometer and documented where each wire goes and thought it might help someone else.

A few pointers for someone that has never removed a gauge or removed bulbs from a gauge...

• Use a plastic pry tool typically used for car door panel removal to help get the gauge out of the dashboard.
• Use a small blade screw driver to help pry the bulbs out. The bulb socket is the plastic and the metal rings so you want to pry below the metal ring.
• The connectors with the double wires use a jumper. I actually thought I was pulling the spade connector out of the speedometer at first, but it was the jumper.

[WolfeMacleod]

Haha. I just had to do this a few weeks ago. Wasn't able to turn the gauge around to take very clear photos.. had to rely on what blurry photos I could grab.
This will come in handy, for sure.

I'll add that I used an interior panel puller to pull the gauge out. Specifically, the 4th or 5th tool from the left in this kit here. Slip it behind the lip, work it around and gently pry out as you go.
https://www.amazon.com/gp/product/B00LUPOU1O/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8

That being said, I am very curious to find out whether a piece of strong fishing line looped behind the lip of the gauge and worked around while pulling on it would do the same thing.

[Pigeye]

Originally Posted by avale

I have an '87 911 and after filling up, pressed the plunger to reset the trip odometer and quickly noticed that trip odometer was no longer working. Gas station is right by my house so only have like 2/10th of a mile that isn't registered on my odometer. I've read all the threads about repairing this myself, but I live a mile away from Palo Alto Speedometer - so that is my repair path. I took a picture of my speedometer and documented where each wire goes and thought it might help someone else.

A few pointers for someone that has never removed a gauge or removed bulbs from a gauge...

• Use a plastic pry tool typically used for car door panel removal to help get the gauge out of the dashboard.
• Use a small blade screw driver to help pry the bulbs out. The bulb socket is the plastic and the metal rings so you want to pry below the metal ring.
• The connectors with the double wires use a jumper. I actually thought I was pulling the spade connector out of the speedometer at first, but it was the jumper.

Brilliant - this diagram will be helpful - I think some wires pulled off when I pulled the gauge - so when I took a picture to document - they were not there and guess what - Speedo didn't work. thanks for this picture!

[FrankM_]

Very useful , thanks for this !

[Pigeye]

This fixed it - all good on speedo. Wish I could say the same for engine

[RedCoupe]

I used this thread to figure out my speedometer wires on my 86 Carrera after I lost the labels on the wiring while the speedo was out being repaired. However, even though my Bentley manual shows the 86 and 87 wiring as the same, my wires were a bit different than the great picture and chart earlier in this thread. Here are how mine worked out:

• + Red/Black wire
• 2 Blank
• A White/Red wire
• 31b green wire, green wire, black/green wire
• - Brown wire, brown wire