More foten than not, my tac doesnt work in my 82 4wd. The neelde just moves up and down very slowly and stixk around 3 grand(even at idling speeds). Any suggestions?

 

mine doesn't work at all after months of doing the same thing. MY tach is toast, yours may be too. time to bust out your multimeter!

 

how exactly does the tach work? Is it electronic or is it some sort of mechanism?

 

It's electronic. There is a green plug coming off the coil that senses the RPMs. Might want to check that connection first since it is the easiest. Trace that wire back and you'll likely find your problem.

Here's a picture of the plug that I found online (it's the plug in the lower right of the picture that isn't hooked up):

 

thanks for the pic man! I am gonna go home today and trace it out. I have had this truck since 2004 when i bought it as my first car in high school. Hasnt been in my possession since 2006 since i have been moving everywhere with the military. Now that I finally have it back again, it still has the SAME two problems it had back in 2004: I craooy tach and that intermittent idling issue everyone talks about.

 

Mine did the same! I didn't run the truck much before the rebuild and I didn't really diagnose it but after researching the net and talking with a couple of people they told me the actual tach was the problem, true or not I don't know, but I plan on putting in an old school aftermarket tach in the original place that will go along with my circa 1984 sunpro gauges.

 

let us know if you find the problem

 

Does anyone know if the tach can be repaired ?
My tach works occasionally on my 1980 4x4.