Efan temperature switch

[Tdean91491]

Yes I’ve read the post about doing the MARKVIII set up, I can’t seem to get my hands on all the parts he has listed in his post. Have any of you guys recently added efans with a temperature switch still a have a parts list ?

 

[kennythewelder]

Here is my write up on what I did on my 97 Silverado, and what temp switch I used, and a pic of the box it came in, with the part #
https://www.gmt400.com/threads/electric-fan-swap-on-the-cheap.41756/#post-1006460

 

[kennythewelder]

I tried a cheap switch at first, but it failed quick. The switch I used is on the second page of the post. Also I run my truck cold, so my temp switch may be colder than you want, but at least you will have a place to start any way. I got it @ Orillys. on @ 175 off @ 190 I think. I have a 170 thermostat. I find my truck runs better a little better cold, and I dont have any cats any more.

 

[Tdean91491]

How do you have the switch wired in? Did you find the correct pigtail for it or did you make do with something? I like the way you added it to the water neck outlet! I’m not a very talented welder but I have some buddy’s at work that could make it happen. What would you suggest to use for the nipple on the housing?

 

[Tdean91491]

I currently have my fans coming on when I turn my ignition on & I thinks causing my truck to run to cool, I know may sound crazy but from what I understand it running to cold isn’t always a good thing. I’m just wanting to put a temp switch on it to see how it affects the way it runs.

 

[kennythewelder]

I work @ a machine shop, so I used a round aluminum bar to make the nipple. Then drilled at taped it. I didnt have a nipple but had round stock. I wired my temp switch to a relay. My fans are wired to a switch on the dash. This will over ride any other switch if I turn it on. A fail safe. I wired into the AC clutch switch, so if the dash switch is off, the AC compressor ( clutch ) will trip the relays on, and the temp sensor, is wired to an extra relay. This relay is wired into the other 2 relays so it will turn on the fans when the AC and dash switches are both off. That way, if the AC i is on, it cant back feed the temp switch. So 1 relay for each fan, and 1 relay for the temp switch that is wired to feed the 2 fan relays on the 2 relay trip wires. I did all my wiring my self. Look close at my write up in the other thread. Its all in there. As for running your truck cooler than OE, we live where it is hot. So I like to run mine cooler. IMO my truck just runs better at a cooler temp. Mine has been that way for years, and it doesnt effect anything in a bad way. At least it hasnt on my truck anyway.

 

[kennythewelder]

Oh and the aluminum nipple does not have any coolant inside of it. I just welded the nipple to the thermostat housing without making a hole in the housing. Heat transfer will be plenty enough to trip the switch.

 

[kennythewelder]

I forgot to mention, my temp switch has 2 leads. The temp switches with just 1 wire, go to ground. Not what I wanted. I wanted to trip a relay, so I wanted to turn on a positive wire, not a ground. I know I could have wired the relay hot on the trip wire, and switch the ground, but I did not want to do it like that. I rather switch the power supply, than the ground. Just my preferance.