[62131]

I'm using two temperature sensors in my wiring. One is used for the temperature gauge and I have it located in the head on the left side of the engine. The second one is going to be used to control the fan. I was going to locate it in the manifold near the goose neck or should it be in the head on the right side?  

[EDNY]

Located on the passenger side the (on/off sending unit) grounding wire will be closer to the firewall ?  I'm sure you are running a relay to power the fan...if so, that wire will go to the relay. You could also split that wire to a toggle inside the should you want a manual override along with the sensor for the fan?

On my TPI engine I let the ECM turn on the low speed fan and have a manual toggle for the high speed. On my son's 37 Chevy with LT1 engine, the ECM controls low and high speed..but I also installed a manual DPDT toggle should he want to override either or both fan speeds.