99 Ranger Tach

[Nathan123]

I have a 99 ranger xlt, it has around 175000 miles on it with the 4.0 litre, 5 speed, and 4x4. The tach basically quit working. Driving down the road it reads 0. Sometimes the needle jumps up to the normal range for a second or two, then just drops to 0. Smacking the top of the dash scan recreate what I'm describing. Is this a busted gauge, or a bad ground wire or something else?

 

[adsm08]

I'd guess bad tach.

Pull the cluster out where you can get at the plugs, back probe the wires for the tach with a voltmeter, and then start it and rev it up and see if the voltage numbers change.