my car is an 88, v-6?, the guy had it before me must have used an 87 spare car to make it tpi, the rear end codes to 87, i ripped out all wiring and put my 86 tbi harness throughout the car. didnt swap gauge clusters cause i wanted to keep 140 mph speedo, all gauges worked right in the 86 car but now i turn headlights on and the volts,tach go crazy and pass blinker light in the cluster is always on when headlights are on ??? signal works fine, not burnt out, i put a new dimmer switch in and same problem i have gone through the wires from the firewall to the lights they r good so i am wondering are gauge clusters any diff from 86 to 87 or any thoughts????