I just got a CRX SI cluster and when i try to plug it in, there was one plug left over it's a blue color plug. I have a 1990 Civic Hatchback.
I plug the other two wires and try it but the RPMs didnts work, oil light was one when i turn on the lights and theres nothing wrong with me wiring because the other cluster didnt do that.
so can someone help me on this one.

 

anyone

 

You might want to look around the net for the shop manuals from each of those cars. They have diagrams of the electricals for the clusters you can then cross reference and see what needs to be plugged in where or where you might need to repin. I don't know exactly what is causing your problems but I'm sure by looking at the diagrams you could come up with a good place to start.

Mike