I have a a 1989 Mustang GT and I was wanting to know if all gauge clusters from 1987-1993 will interchange or if I will have to modify my wiring? Thanks.
Yes, they interchange but the 90-93 is not just a plug and go affair into an 87-89 car. You'll need to re-pin both harness's and lengthen some wires. Its not difficult to do, just a little time consuming...the tricky part is figuring out what wires go where,lol. You will also need the 90-93 instrument cluster shroud(bezel). I recently put a 90-93 140mph cluster into my 88 along with the airbag wheel/column. The wheel/column is a bolt in affair, although the horn/airbag won't work. Also, you'll need to re-pin the wiper harness as well, as they are wired different.
So in other words...its easier to just get an 87-89 140mph cluster or speedo. Brothers Performance will calibrate your 85mph speedo with a 180mph overlay...as thats all they had in stock when i called and asked about it. $69 if i remember right. I had this 90-93 cluster laying around so i went that route.