I know this has probably been discussed but have been searching the forhns for two days now and haven't found what I'm looking for... I got a 87 camaro with a 355 small block carbureted and a single electric fan previous owner wired up. I have a set a dual electric fans from a 99 camaro that I'd like to install along with a high/low/off switch on the dash so I can run them on different speeds instead of high all the time like my current single fan. Can someone explain or help me with wiring this up? I'd greatly appreciate it.

 

Start here

http://www.austinthirdgen.org/?pid=19

 

I don't know if the LS1 fans have a dual speed or not. Just to wire them up for one speed is fairly straightforward if you just want to use a switch in the cabin. Only advice to give is to use a switched power wire for the switch in the cabin that will energize the relay. That way if they won't accidentally be left on and drain your battery.

 

Lots of useful info in that site but my current t engine setup doesn't have a ECM anymore. And alot of the wiring diagrams show to use ECM power

 

They are just having the ecm ground out the negative side of the energizing coil of the relay. All you would have to do is replace the ecm with a switch that has the other end grounded.