Speedometer/Odometer Stopped Working

[PorscheNerd]

I've been searching the forum on this with partial luck. While sitting in traffic at a stop in my 77 Targa, the speedo needle started to bounce around. Up to 100 and then settled down. Now neither the speedo or odometer work. I'm going to pull the speedo and check connections. Any way to check the cable?

[80-911SC]

yes ... disconnect at the tranny and at the speedo ....

the cable run in the little tube that connects them and turns really fast ....

[kodioneill]

I don't know how the cable could move with the car standing to make the speedo jump like that?

[tobluforu]

Isn't this an electrical speedo?

[PorscheNerd]

So I pulled the speedo and pulled on the connections. It started to work again and then 20 miles later it started to sputter around and stopped. I guess it's an electric speedo as there was no cable on the back side just electrical connections. I did notice that the speedo was rebuilt in 1984 at 54000 miles. Maybe time to send it in for a rebuild? Maybe clean all of the connections?

[jfkruse]

PorscheNerd,
Had the same problem with my 83 SC. My car is an electrical speedo/odometer. I recently changed my instrument Lights to LEDs ala Etarga, and my coupler bushings ala Ed Mitchell.
Checked my instrument wiring, cleaning at the same time, no correction to speedo, (it was dead as a door nail). Checked the tunnel where the coupler resides just forward of the rear seats, looking at the speedo sensor wire connection on the right side of the tunnel. Guess what, the connection on one of the wires leading to the speedo was separated. Cleaned up the terminals and bango back in business. I had the thought I my be shipping the speedo out to California for an overhaul. I must have dislodged the connection on replacing my shift coupler.

JKruse

[PorscheNerd]

Originally Posted by jfkruse

PorscheNerd,
Had the same problem with my 83 SC. My car is an electrical speedo/odometer. I recently changed my instrument Lights to LEDs ala Etarga, and my coupler bushings ala Ed Mitchell.
Checked my instrument wiring, cleaning at the same time, no correction to speedo, (it was dead as a door nail). Checked the tunnel where the coupler resides just forward of the rear seats, looking at the speedo sensor wire connection on the right side of the tunnel. Guess what, the connection on one of the wires leading to the speedo was separated. Cleaned up the terminals and bango back in business. I had the thought I my be shipping the speedo out to California for an overhaul. I must have dislodged the connection on replacing my shift coupler.

JKruse

Gonna check that next! Got it working for another 5 miles and it went wonky all over again!

[86 911 Targa]

And when you re-connect: