97 f150 st/sd larriat w/150k! My tachometer keeps jumping around! It works when it wants to! What can I try first before having to replace it? I found one at a Junkyard! Can I just fix the tachometer.or do I have to replace the whole instrument cluster?

 

You can try the cluster, but you may have to take it to a dealer for the junkyard cluster to work.

 

Try this link to see if you'd like to tackle repairing your own cluster: https://www.ford-trucks.com/forums/1...r-anatomy.html

That's something I did thinking I'd modify either my van wiring or a cluster in order to add a factory tach.

 

Not on a 97 or 98 F-series trucks (not SUVs). It wasn't until 99 that PATS was added to the cluster that the dealer's participation became needed.