I just purchased a 90 teg jdm cluster and plan to install it into my 90 usdm teg.Is there anything I have to do for wiring so it will work? Or do I just need to plug it in?

 

just plug it in.... depending on what options your car has the new cluster may not have the appropriate lights (i.e. abs, cruise....). So if you want to you can also pull the tach out of the jdm clutser and put it into your usdm cluster. That is if you bought the cluster for the higher rpm tach, which I imagine you did.