I'm running a computer out of a 91 beretta GTZ and the wires to the instrument cluster are gone. I have a complete 89 Grand AM with the 2.3. I was wondering if somebody could help tell me which terminal or wire to use on the Grand Am cluster to make the tach work? Haynes man. for the GTZ says white wire from computer is tach out put but not sure where to tie into the new cluster. I just need tach as its a circle track car. thank you for any help.