Fan control

[DOUBLEC]

Not sure if this is the right venu for this question but here it goes.

I have a 1977 CJ7 258 I6 that I got tired of fighting emissions every year. After a lot of research I decided to do the 4.0 head swap. I'm nearing the end of the project and working on the cooling.

I picked up a 2 speed fan from a Ford Taurus, again a lot of research, and decided to lay out a circuit design which I have attached if anyone wants to use it. It's a bit busy and most likely way over kill for most.

I would like to use the ECU to control the high speed fan. I did a lot of research on the temp cut in, anyware from 90 to 215 degrees. At 215 I figure things will start melting down.

So my question is has anyone out measured the temp when the ECU activates the signal.


View attachment FAN CONTROL.pdf

 

[superj]

no, but there is a huge thread on another forum about using the fan controller from a volvo because it comes in its own sealed box and it has the high and low controller built into this one little black box. supposed it is super easy to find, just follow the wiring from the volvo fan back past the head lights a little and its right there. just hook up your wires and go.

bu no idea on the temp stuff when the ecu kicks in but i know most of our jeeps run at about 210 normally

 

[DOUBLEC]

no, but there is a huge thread on another forum about using the fan controller from a volvo because it comes in its own sealed box and it has the high and low controller built into this one little black box. supposed it is super easy to find, just follow the wiring from the volvo fan back past the head lights a little and its right there. just hook up your wires and go.

bu no idea on the temp stuff when the ecu kicks in but i know most of our jeeps run at about 210 normally

I must have spent 8 hrs looking at the million threads on this subject, missed the Volvo one. I'll start looking for it today. Thx for the info

 

[JPNinPA]

Typically there is a module either with a temp probe or splice into the temp sending unit. Either way they are not getting the signal from the PCM.

 

[Jester32]

Chevy camaro with electric fans lt1 and v6 have a coolant switch that switches on at 195. I run that to a relay. And it's done. Use it on all my hot rods. Simply and very easy to find. It just screws into a coolant port and is just 1/2 inch thread.