I can't find anything of substance about speedometer failures with 850's. I have two 850 GLT's. A 96 and a 97. My 96's speedo rarely works for the past several years. Sometimes it comes to life then just stops. My 97 the speedo works most of the time but once in awhile it just stops too. If I turn off the ignition then restart the speedo works. I want to know what causes this, and what is the remedy is? If there is anyone on the site with knowledge regarding this type of problem I would love to take care of this but not sure where to start.

 

could be the speed sensor or could be the cluster has a loose connection or could be the ABS controller board (prone to cracks in solder joints)

 

You might want to look into the gears inside the cluster.

Video is from one of our members, Robert.

 

Robert's videos are always very informative. I had a suspicion it could be the ABS controller because both cars have the TRACS lit all the time too. Speed sensor would be great as it is a less expensive item to replace. Thank You!