Join Date: Feb 2009
Location: Largo, FL 33774
I would wire the switch to ground the relay, not power it. Since you are using a switch, you can use a hot in run/test/acc. wire, and you can leave the switch on, unless you want to turn it off. You can also use an always hot wire. Make sure you fuse the circuit. You could even connect it directly to the battery with a fuse, but you must remember to turn it off when you stop the car. If you are going to ground the relay with the switch, you can use the same hot wire to power both the coil, and hot input of the relay. Check the wattage of the fan, and use an appropriate size wire, and fuse. You could also use the hot in run/test/acc. to power the coil, and connect the power for the fan directly to the battery with an appropriate fuse.
Red and black is usually a hot in run/test/acc. It is a small gauge wire, so do not use it for the main power for the fan.
I am not sure why you are putting a lead to the PCM. If you are going manual, you do not need anything from the PCM.
1991 OCC 461 (.030 over 454) BBC, 3.23 posi, flash to pass, drop spindles & springs, Impala rims, Hydroboost, Recaros, MOMO/wood SW w/QR, custom wood shift knob, Pioneer DEH P77DH
1992 OCC now with 5.7 tbi, DEH P77DH
For a parts list, check https://www.impalassforum.com/vBulle...ion-parts.html
Last edited by Fred Kiehl; 11-22-2017 at 03:39 PM.