tach issues

[$TheMoneyPit$]

i have a 1992 mazda navajo that has some issues but the most annoying at all is my tach will work fine if i dont drive my truck for a while it will function as its supposed to but then will spike up to 3100 and will not move unless i go past 3100 its werid because the truck is not actually idling at that rpm i have actually watched it spike between its actual rpm while driving at 2100 and jump to 3100 and go back now its stuck there and is really a pain in the neck any ideas of how to fix it or where i should actually look thanks

 

[WarriorExplorer]

yeah I have had the same problem in my 92 Expo for years. Would love to find a solution.

 

[Riceburner247]

Notorious problem.

http://www.explorerforum.com/forums/showthread.php?t=129889&highlight=Tach
http://www.explorerforum.com/forums/showthread.php?t=196243&highlight=tach

 

[$TheMoneyPit$]

what year clusters can i use that will hook right up wiring wise and speedo cable wise i know 1991 to 1994 navajos but what year explorers can i go up to