Hi I have a 84 928 speedo not working. Replaced speedo head. (928 intn'l). checked the pulse sensor connections checked terminals near battery box everything seemed ok. checked the instrument cluster plugs ins (3) checked for grounds at steering column and back of instrument speedo head they were grounded properly. Checked for power in back of speedo head had 9volts. checked the pulse sensor power side and it registered 2.5 volts. The big question is are these the correct voltage readings. I am stuck on diagnosing this speedo situation. The cruise control works if that means anything. Much appreciated

 

Is the tempostat plug above the radio? Center dash underneath?

 

thanks much

 

I checked at the tempostat, and moved the car back and forth, and on pin 11 and 12 i got the proper readings. Can the tempostat itself cause the speedo to not work? How do you test the tempostat unit itself? Anyone out there experience these kind of problems and what was the fix?

 

If the cruise control works, the sensor and wiring to the Central Electric Panel are OK.

If both the speedometer and odometer are dead, but the cruise control works, the most likely problem is a faulty connection on the instrument panel foil or connectors.

 

does that go for the 81 model also?i have checked the connection in the battery box,couldnt find a fuse for it but all fuses clean and good.

 

took the instrument cluster to the speedo shop, and cluster is faulty somewhere, I will post when I pick it up begining of next week. I did replace the speedo head from 928 international must be in the cheesy plastic wiring

 

I think Dwayne traced it to corrosion about the rivets in the film on his 84 speedo / pod repair project.

 

82-84 Porsche 928 Gauge Cluster Printed Circuit Replacement

SKU: LTZ-92864197301
https://www.lutzauto.com/product-page/LTZ-92864197301

https://www.lutzauto.com/porsche