Switch for fan clutch

[DMcGalliard]

I want to be able to switch the engine fan on manually. I have seen Matt 400's diagram and was wondering if it is different for an 05. My 05 with a six speed with 3. 73 and it will get up to 217-220 before the fan comes on a hard pull with my 15k fifth wheel, turn the air on and the fan will come and cool down. Don't like to run the air when not needed just to get the fan to come on. What is the size of the resistor for the 05. Would appreciate input from Matt 400 or anyone who has done it.



Thanks Dave Mc

 

[Cattletrkr]

I'd be interested in that as well.

 

[Matt400]

I did that to my 03 but haven't to my 05.

I do know the CTS is different between those years so you would need a different resistor to properly fool the ECM.



Basically you splice in a toggle to the CTS circuit so when you flip it, it takes the CTS out of the circuit and instead the ECM sees the return voltage from what ever resistor is in place. The one on my 03 simply told the ECM that coolant temp was 220 so the ECM engaged the fan.



I did it for backing a trailer to keep air moving over the trans cooler, helped egt's come down too after a long climb when I wanted to shut down the engine.

IMO your 217-220 is just right, turning it on sooner would just hurt mpg's and performance.

 

[sfr1047]

Matt,

Can you post that diagram and info you used for your 03?

 

[Matt400]

Check post #21 on this link:

https://www.turbodieselregister.com...3-2007/129688-transmission-temperature-2.html

 

[sfr1047]

Thanks Matt, Now to figure out what size resistor to use for my 04.

 

[Matt400]

Thanks Matt, Now to figure out what size resistor to use for my 04.

I remembered doing some research on that some time ago so went through some old notes. . I think you will find that 700 ohms will work well for the 04.

 

[sfr1047]

Thanks Matt, I will put that info in my stack of things to do.



Dave B