I have an aftermarket Bosch tach. I recently started bouncing between reading correct and double.

Doesn't effect how the truck drives, just is annoying.

Thanks, Adam

 

Reads like time for a new Tachometer

 

Boo, that sucks. This think is only about 6 months old.

 

Then I wouldn't get that brand again

You don't mention the YEAR of the Ranger?
Most years did had an in dash Tach option so you can swap in a new cluster that has a tach built in, the tach wiring is already there for this in most years

 

It's a '93. I'll look around the junkyard to see if there is one with a tach in the cluster.

 

1993 and 1994 are the only matches so might be hard to find

 

Just curious, did you wire the tach yourself? I remember that I installed a tach in my old isuzu truck and it would act funny on hot days or after long drives. Turns out the cruddy clamp on splices they provided with the tach would swell in the heat and cause continuity issues. Double check your wiring, and if you didn't already, solder and heat shrink your connections. Might just fix the issues.