PLEASE HELP - TACH ISSUES AFTER I FIXED SPEDO

[Peabody]

HI,
I am really upset, every time I try to fix something on my car it causes problems.

90 S13 Original Owner

I has problems with my speedo staying at 45 or only reading up to 15 MPH, ETC.. I was told it was not the speed sensor and was told to replace the speedometer. I bought a working cluster from another 90 s13 and installed it. It fixed my speedo issues but now my tach is not working. I put back my original cluster and the speedo acts up like usually and not THAT tach does not work.

What could I have done. Everything else works fine but the tach will only move a tiny bit when I start the engine but then sits at 0 RPM. I was very careful and cannot understand how now 2 Tachs are not working.

ANY SUGGESTIONS>>

THANKS.

[Peabody]

The problem was the person that sold me the cluster said it was from a 1990. After messing with it ALL DAY I found out it was from a 1991. The 7000 RPM red line should have gave it away.
I did just put his Spedo in my original cluster and now it all works.

THANKS