International Lancia Forums

My speedometer died now, this is an electronic one, and has anyone been in touch with this before? -90 Thema Turbo16V


Martin

Hi,
My experience with Deltas, Prismas and Themas is that it is the sender unit at the gearbox which fails. They usually become intermittant then die.

Leo

I would go along with Leo's answer fairly common fault on Dedra as well.

This is a wery common problem on Themas. The fault can be in the gearbox sensor or in the dashboard. Someone also told me that the problem can be due to a stuck km counter! I dont know if that is true. A gearbox sensor will set you 70 pounds back and a used dashboard (yes you probably have to get a hole dashboard) will cost 90 pounds (a least in Denmark, expensive country!). God luck!
Villads Bønding

Another possible fault could be the famous Thema instrument-panel grounding problem.
I belive that the spedometer is the first instrument that will stop working due to the grounding problem.

It is easy to determine if you have a grounding problem, just closly watch th volage meter as you turn on the turning indicators. If the voltagemeter starts to dip you have a grounding problem.

A good garage can measure the output of the sending unit, to determine if it is working corectly.

(I actualy lost my speedometer due to a problem with the connector between the sending unit and the instrument-panel, a mechanic had pulled a bit on the cable and one of the metal pieces in the connector had moved causning an intermittent speedometer loss.)

I had this problem which took me two years to find!
I changed the gear box sendor no luck,
the reciever p.c.b board on the back of the instrument panel,
and the speedometer its self. I also checked all the wiring from the sender to the reciever, still no luck until I noticed a electronic component called a diode in between the two layers of the copper track on the back of the instrument panel, this had gone open circuit!!!

At last with it fixed i finally knew why i kept getting speeding tickets

Good luck

I solved the problem by getting a wire instead.

Christian

Do you mean you replaced the diode with a piece of wire.