So I have a 1986 Iroc, which has the ecm controlled single fan. No fan switch. Currently have a 3 core rad from Mishimoto with the stock fan and shroud. Also should add I have a 180 thermostat with the ecm turning it on at 190. Usually the temp is okay but its been extremely hot and the stock fan just isn't keeping up in stop and go traffic. It never shut off for a 30 minute drive home today with temps in the mid 90s.

I am looking at upgrades to the stock fan that will work with the ecm. Would a dual fan setup be better? Ive read the LS1 fan and shroud combo are a direct bolt in. Just not sure exactly how to wire up both fans to work with the ecm.

 

In my mind, I would wire the dual setup like the factory later models.
One side: wired (spliced) to existing fan wiring (ECM triggered at 190 as you mentioned)
Other side: block coolant switch EG ( )

That way you get the redundancy of two systems should one fail or read different. The kit listed has a 3/8" NPT fitting, double check that size will fit in your block. I believe port is between cyl 4 & 6

 

Install LS1 fan set up and then have a separate power circuit for the second fan but have it ground to when the first fan comes on. at the relay. I think that's where the gerund wire is at.


use 1 factory motor and then one LS1 motor becuase 2 - LS1 motors will over tax your charging system with lights, ac, brakes on etc...

 

Plus you can make it look stock!