some say it's a diod issue but i have no clue. I'm a highschool automotive student and i need to have information on why my tach reads backwards and or says it's idling at 8000 rpm. Please help!!

 

https://www.thirdgen.org/forums/v6/5...tach-sale.html

Basically the resistor is bad, unfortunately, none of us actually know what voltage a good one is supposed to have...

 

This is most likely the answer to your question. https://www.thirdgen.org/forums/elec...meter-fix.html It cost about $2 to $5 to get the part to fix and can be done in 15 minutes.

 

That thread posted above will save your life PDXRS. However, reading through it, it doesn't help us 3rd gen. All it basically states throughout the thread is to solve the bad reading problem you have to install 2 100k ohm resistors to have it read correctly.

 

Here is the easiest fix: go to the junkyard and find a 91 or 92 with the same gauge cluster. Drop the steering column(not absolutely necessary but it makes it way easier), pull the front cover off the cluster and you will see a small circuit board below the tach- pull this out, stuff it in your pocket, go home and swap it into your car. It should work immediately unless that board is bad too(not likely).

 

Hey thanks for the replys! so what i need is 2 100k ohm resistors ? and Motormouth i have seen that thread but there is soo many responses that i can't find out what exactly i need. It's a v6 3.1

 

If you know your motor idles at the correct RPM start with 180 and go from there. If it's to high use less ohms. If it's to low use more ohms and report the correct number to help the others having the problem.