Blown88GT
Founding Member
Transplanting harness & electronics from one year to another is difficult if not impossible due to Ford changing things, even within the same year. Almost better to purchase a new harness, rip out the old, & start over. At least, you're starting over with brand new wire & connectors. LMR has everything.
https://lmr.com/item/CAS-5500/mustang-classic-dash-gauge-harness-87-89
https://lmr.com/item/CAS-5500/mustang-classic-dash-gauge-harness-87-89