1998 Volvo S70 Q&A
1998 Volvo S70 Question: What causes speed odometer malfunction ?
There's a sensor which works with the speedometer you need to replace that sensor - sinautoscan.com
The speedometer receives a vehicle speed signal from the ABS Control Module. If the speedometer is not working, I would look at the ABS module (very common on this vehicle) for faults and address that first. Have you had a problem with the ABS lights coming on? If there are other electrical issues at the same time, like the radio not working or the dash lights not working, then the electrical portion of the ignition switch may be having issues, which is another common problem on this Volvo. - Bret Bodas