Hi, I have searched the archives and am still unclear on how to hook up a tach to my 92. I found the plug with the grey/black wire inder the dash as part of the 4wire plug, and am not sure if I need a special diesel tach at this point. Any advice? Thanks

 

Is the tach that you have a factory or aftermarket tach(if aftremarket then what type)?

 

I don't have the tach yet but i am planning on getting the isspro 0-4k

 

The sticky has an awesome write-up by BC847, you should read it.