Okay my 89 RS 305 TBI Overheats The Fan Dont Work So I Want to Know How Can I Wire It To Automatically Turn On when it Reaches Anywhere from 180°to195°? Supplies i have are a 1.Fan 2.Connectors Power & Ground ...3.Fan Relays And 4.Fuses... 5.195° Thermostat Installed 6.New Radiator My Hoses & Water Pump & Heater Core are Also New Help Please Thanks...

Get a fan switch for a Buick GN and stick it in the passenger side head. Use it as a ground trigger to energize the relay which will turn on the fan.

Thanks for the Replies Guys

A list of switches
https://www.thirdgen.org/forums/cool...ilability.html

Just get this ($16):

1. Thermostat Switch

2. Install that thermo switch properly and connect the triggered contacts to ground on one side and to the green/white wire on your factory fan relay on the other. (Red doodle)

If you have the dual fan, connect it to the green/white wire of the relay that triggers the passenger side fan (this is the Heavy Duty Fan). When this triggers, the ECM should also trigger the primary fan. (Blue Doodle)

If it doesn't trigger the other fan, then simple connect both of the green/white wires of the two fan relays together.

That should do it. You adjust the thermo switch to where you want it. I run this on my car and it works great.

Tips:

Insert the thermo switch temp probe through the radiator fins (not alongside it).

Thanks Alot Guys It Really Helps Out

Good luck!

Here do this, don't use a radiator sensor version take the fan switch temp off the head

Isn't that location used by the temp gauge?

There is another port on the other head on the other side of the engine

Not bad... Replace the fuse with a fusible link, and make sure the relay is a weather proof design. Pick up the battery voltage at an existing junction block, most commonly the starter on thirdgens...