i have an 86 trans am , i dropped a built 355 tpi in there, with a aluminum 3 row rad, the ecm and wiring is from a 87 iroc, i deleted the a/c, even the heater, only gonna drive in summer when weather is good. now my question,, i dont have dual fans in the car i have the stock 86 single fan, since i dont have a/c , and i deleted half the harness to have only one relay to my fan,,,, now what should i use to trigger that single fan? i have, 1. the stock temp switch on pass head,2.a temp switch on my new rad 3. the ecm that takes the info from that temp switch on the intake below throttle body, can i use the gre/wh wire from the ecm and both switches on the same relay?? should i rely only on ecm? only on 1 switch? 2 switches? if i use the ecm at all,,,, since i have an 87 wiring, do i ground, or open the blue wire from the a/c? cause i dont have a/c ,,,the car i took the ecm and wire from used to have a/c. if i dont use the ecm,, can i just leave it like that or is there something i should change not to mess up anything,,,,,, i just dont wanna try a bunch of things, want to wire the car properly once,, and hide harness with loom once and for all,thanks.sorry for the looooong question

 

C1 of the 1227165 ecm will control the ground side trigger of your relay. The ecm uses the ect reading and the calibrated temp set in your memcal to turn on the fan usually around 226F. Wiring it this way is better than using a temp sensor that grounds mounted in the head.If your worried about the ecm not grounding the fan relay you can alway wire a second switch in the head and connect to the wire going back to c1 of the ecm.