I have read about installing a manual fan switch and how to do and how they work.

I have been considering running a switch that will allow me to turn my fans on, but also finding a way for the fans to come on with the system like they were designed to do. My question is, has anyone ran a switch that allows the fans to work both ways (manually and also coming on with the system)?

Any help or advice in direction to go would be appreciated. TIA

john

 

top of the page willie covers it.

 

yeah basically u dont need to do any cutting wires, just splicing into the grounding wires going to the relays.

 

Ive got a 90 IROC 355ci, the car has two fans one(drivers side) is the primary fan, used for normal cooling, and a secondary fan
thats used for A/C (called H/D fan) and or temp overheat, I never use a/c while driving anyways, so I disconnected a/c-overtemp fan relay and connected both cooling fan relays to primary relay input from ecm,

now both fans come on instead of just one, the ecm can drive both relays fine with out overloading output,

Im a GM tech, and just thought i would try this on my car,
cuz It ran a little hot with a factory style radiator, and I was very pleases with this mod, pulls down that engine temp nice!

my secondary fan never ran, sitting there just adding weight, now It's pulling It's weight