failing sucks

well.....i put my 89 si cluster in my new 91 std. and everything looked great, looked like it came that way stock.....then for the road test.....i took the car out....and the speedo, and fuel guage's worked but the tach, and temp guage's didnt.......anybody know where i could have went wrong>?the connectors were exactly the same..... but the 91 cluster has 1 more connector....it goes to a little box that has 2 wires going out of it on to 2 diff screws....so i put that on my 89 si tach the same way.....but i failed....it was still not woking right...

I have an 89 DX and tried swapping a 91 SI cluster into my car. I had the same problem you did. My solution was to sell it and buy an 89 SI cluster which worked fine. Apparently the 88-89 and 90-91 clusters are not interchangeable unless you do some additional wiring.