I have a 1991 Volvo 740 wagon and the speedometer works part of the time, then it will stop working.Actually it works when it wants to.

Elbert, August 2008

The speedometer just stopped working this morning... Any way I can fix it quick?

Joe, April 2010

you would probably screw it up trying... this needle and face plate don't seem to come off at all...

me, November 2009

If both the speedometer and the odometer quit, check the sensor connection and wires at the differential.

If the odometer works when the speedo stops working, then it is most likely problems with the electrolytic capacitors on the circuit board of the speedometer. This is a common problem. Pull the speedometer from the instrument cluster, remove the needle and face plate to access the capacitors. There are two or three electrolytic capacitors that have a tendency to leak electrolyte (hard black deposit) onto the circuit board and short pins of the chips. Clean the board and replace faulty capacitors.
Visit the following link:
http://www.brickboard.com/FAQ/700-900/

Michael

Michael (User name 'Bolbo' at www.brickboard.com), October 2008

Its going to be a faulty speedo gauge or a faulty circuit board you need to remove and inspect both as you cant define which one is faulty, there is no way of testing them so you may have to replace both or use salvage parts.

Jack, August 2008